1
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Wilhelm KB, Vissa A, Groves JT. Differential roles of kinetic on- and off-rates in T-cell receptor signal integration revealed with a modified Fab'-DNA ligand. Proc Natl Acad Sci U S A 2024; 121:e2406680121. [PMID: 39298491 DOI: 10.1073/pnas.2406680121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2024] [Accepted: 08/05/2024] [Indexed: 09/21/2024] Open
Abstract
Antibody-derived T-cell receptor (TCR) agonists are commonly used to activate T cells. While antibodies can trigger TCRs regardless of clonotype, they bypass native T cell signal integration mechanisms that rely on monovalent, membrane-associated, and relatively weakly binding ligand in the context of cellular adhesion. Commonly used antibodies and their derivatives bind much more strongly than native peptide major histocompatibility complex (pMHC) ligands bind their cognate TCRs. Because ligand dwell time is a critical parameter that tightly correlates with physiological function of the TCR signaling system, there is a general need, both in research and therapeutics, for universal TCR ligands with controlled kinetic binding parameters. To this end, we have introduced point mutations into recombinantly expressed α-TCRβ H57 Fab to modulate the dwell time of monovalent Fab binding to TCR. When tethered to a supported lipid bilayer via DNA complementation, these monovalent Fab'-DNA ligands activate T cells with potencies well-correlated with their TCR binding dwell time. Single-molecule tracking studies in live T cells reveal that individual binding events between Fab'-DNA ligands and TCRs elicit local signaling responses closely resembling native pMHC. The unique combination of high on- and off-rates of the H57 R97L mutant enables direct observations of cooperative interplay between ligand binding and TCR-proximal condensation of the linker for activation of T cells, which is not readily visualized with pMHC. This work provides insights into how T cells integrate kinetic information from TCR ligands and introduces a method to develop affinity panels for polyclonal T cells, such as cells from a human patient.
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MESH Headings
- Humans
- Kinetics
- Ligands
- Signal Transduction
- Immunoglobulin Fab Fragments/metabolism
- Immunoglobulin Fab Fragments/immunology
- Immunoglobulin Fab Fragments/chemistry
- Immunoglobulin Fab Fragments/genetics
- T-Lymphocytes/immunology
- T-Lymphocytes/metabolism
- DNA/metabolism
- Receptors, Antigen, T-Cell/metabolism
- Receptors, Antigen, T-Cell/immunology
- Protein Binding
- Receptors, Antigen, T-Cell, alpha-beta/genetics
- Receptors, Antigen, T-Cell, alpha-beta/metabolism
- Receptors, Antigen, T-Cell, alpha-beta/immunology
- Lymphocyte Activation
- Point Mutation
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Affiliation(s)
- Kiera B Wilhelm
- Department of Chemistry, University of California-Berkeley, Berkeley, CA 94720
| | - Anand Vissa
- Department of Chemistry, University of California-Berkeley, Berkeley, CA 94720
| | - Jay T Groves
- Department of Chemistry, University of California-Berkeley, Berkeley, CA 94720
- Division of Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, CA 94720
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2
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Schrangl L, Mühlgrabner V, Platzer R, Kellner F, Wieland J, Obst R, Toca-Herrera JL, Huppa JB, Schütz GJ, Göhring J. Advanced Quantification of Receptor-Ligand Interaction Lifetimes via Single-Molecule FRET Microscopy. Biomolecules 2024; 14:1001. [PMID: 39199389 PMCID: PMC11352576 DOI: 10.3390/biom14081001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2024] [Revised: 08/05/2024] [Accepted: 08/07/2024] [Indexed: 09/01/2024] Open
Abstract
Receptor-ligand interactions at cell interfaces initiate signaling cascades essential for cellular communication and effector functions. Specifically, T cell receptor (TCR) interactions with pathogen-derived peptides presented by the major histocompatibility complex (pMHC) molecules on antigen-presenting cells are crucial for T cell activation. The binding duration, or dwell time, of TCR-pMHC interactions correlates with downstream signaling efficacy, with strong agonists exhibiting longer lifetimes compared to weak agonists. Traditional surface plasmon resonance (SPR) methods quantify 3D affinity but lack cellular context and fail to account for factors like membrane fluctuations. In the recent years, single-molecule Förster resonance energy transfer (smFRET) has been applied to measure 2D binding kinetics of TCR-pMHC interactions in a cellular context. Here, we introduce a rigorous mathematical model based on survival analysis to determine exponentially distributed receptor-ligand interaction lifetimes, verified through simulated data. Additionally, we developed a comprehensive analysis pipeline to extract interaction lifetimes from raw microscopy images, demonstrating the model's accuracy and robustness across multiple TCR-pMHC pairs. Our new software suite automates data processing to enhance throughput and reduce bias. This methodology provides a refined tool for investigating T cell activation mechanisms, offering insights into immune response modulation.
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Affiliation(s)
- Lukas Schrangl
- Institute of Biophysics, Department of Bionanosciences, University of Natural Resources and Life Sciences, Muthgasse 11, 1190 Vienna, Austria; (L.S.)
- Institute of Applied Physics, TU Wien, Wiedner Hauptstr. 8-10, 1040 Vienna, Austria
| | - Vanessa Mühlgrabner
- Institute for Hygiene and Applied Immunology, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Lazarettgasse 19, 1090 Vienna, Austria
| | - René Platzer
- Institute for Hygiene and Applied Immunology, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Lazarettgasse 19, 1090 Vienna, Austria
| | - Florian Kellner
- Institute for Hygiene and Applied Immunology, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Lazarettgasse 19, 1090 Vienna, Austria
| | - Josephine Wieland
- Institute for Immunology, Biomedical Center, Medical Faculty, Ludwig-Maximilians-Universität München, 82152 Planegg-Martinsried, Germany
| | - Reinhard Obst
- Institute for Immunology, Biomedical Center, Medical Faculty, Ludwig-Maximilians-Universität München, 82152 Planegg-Martinsried, Germany
| | - José L. Toca-Herrera
- Institute of Biophysics, Department of Bionanosciences, University of Natural Resources and Life Sciences, Muthgasse 11, 1190 Vienna, Austria; (L.S.)
| | - Johannes B. Huppa
- Institute for Hygiene and Applied Immunology, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Lazarettgasse 19, 1090 Vienna, Austria
| | - Gerhard J. Schütz
- Institute of Applied Physics, TU Wien, Wiedner Hauptstr. 8-10, 1040 Vienna, Austria
| | - Janett Göhring
- Institute for Hygiene and Applied Immunology, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Lazarettgasse 19, 1090 Vienna, Austria
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3
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Rogers J, Bajur AT, Salaita K, Spillane KM. Mechanical control of antigen detection and discrimination by T and B cell receptors. Biophys J 2024; 123:2234-2255. [PMID: 38794795 PMCID: PMC11331051 DOI: 10.1016/j.bpj.2024.05.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2024] [Revised: 05/10/2024] [Accepted: 05/21/2024] [Indexed: 05/26/2024] Open
Abstract
The adaptive immune response is orchestrated by just two cell types, T cells and B cells. Both cells possess the remarkable ability to recognize virtually any antigen through their respective antigen receptors-the T cell receptor (TCR) and B cell receptor (BCR). Despite extensive investigations into the biochemical signaling events triggered by antigen recognition in these cells, our ability to predict or control the outcome of T and B cell activation remains elusive. This challenge is compounded by the sensitivity of T and B cells to the biophysical properties of antigens and the cells presenting them-a phenomenon we are just beginning to understand. Recent insights underscore the central role of mechanical forces in this process, governing the conformation, signaling activity, and spatial organization of TCRs and BCRs within the cell membrane, ultimately eliciting distinct cellular responses. Traditionally, T cells and B cells have been studied independently, with researchers working in parallel to decipher the mechanisms of activation. While these investigations have unveiled many overlaps in how these cell types sense and respond to antigens, notable differences exist. To fully grasp their biology and harness it for therapeutic purposes, these distinctions must be considered. This review compares and contrasts the TCR and BCR, placing emphasis on the role of mechanical force in regulating the activity of both receptors to shape cellular and humoral adaptive immune responses.
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Affiliation(s)
- Jhordan Rogers
- Department of Chemistry, Emory University, Atlanta, Georgia
| | - Anna T Bajur
- Department of Physics, King's College London, London, United Kingdom; Randall Centre for Cell and Molecular Biophysics, King's College London, London, United Kingdom
| | - Khalid Salaita
- Department of Chemistry, Emory University, Atlanta, Georgia; Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia.
| | - Katelyn M Spillane
- Department of Physics, King's College London, London, United Kingdom; Randall Centre for Cell and Molecular Biophysics, King's College London, London, United Kingdom; Department of Life Sciences, Imperial College London, London, United Kingdom.
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4
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Morita S, O'Dair MK, Groves JT. Discrete protein condensation events govern calcium signal dynamics in T cells. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.31.606035. [PMID: 39211144 PMCID: PMC11360922 DOI: 10.1101/2024.07.31.606035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/04/2024]
Abstract
Calcium level variations, which occur downstream of T cell receptor (TCR) signaling, are an essential aspect of T cell antigen recognition. Although coordinated ion channel activities are known to drive calcium oscillations in other cell types, observations of nonperiodic and heterogeneous calcium patterns in T cells are inconsistent with this mechanism. Here, we track the complete ensemble of individual molecular peptide-major histocompatibility complex (pMHC) binding events to TCR, while simultaneously imaging LAT condensation events and calcium level. Individual LAT condensates induce a rapid and additive calcium response, which quickly attenuates upon condensate dissolution. No evidence of cooperativity between LAT condensates or oscillatory calcium response was detected. These results reveal stochastic LAT protein condensation events as a primary driver of calcium signal dynamics in T cells. One-Sentence Summary Ca 2+ fluctuations in T cells reflect stochastic protein condensation events triggered by single molecular antigen-TCR binding.
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5
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Shi J, Yin W, Chen W. Mathematical models of TCR initial triggering. Front Immunol 2024; 15:1411614. [PMID: 39091495 PMCID: PMC11291225 DOI: 10.3389/fimmu.2024.1411614] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2024] [Accepted: 07/05/2024] [Indexed: 08/04/2024] Open
Abstract
T cell receptors (TCRs) play crucial roles in regulating T cell response by rapidly and accurately recognizing foreign and non-self antigens. The process involves multiple molecules and regulatory mechanisms, forming a complex network to achieve effective antigen recognition. Mathematical modeling techniques can help unravel the intricate network of TCR signaling and identify key regulators that govern it. In this review, we introduce and briefly discuss relevant mathematical models of TCR initial triggering, with a focus on kinetic proofreading (KPR) models with different modified structures. We compare the topology structures, biological hypotheses, parameter choices, and simulation performance of each model, and summarize the advantages and limitations of them. Further studies on TCR modeling design, aiming for an optimized balance of specificity and sensitivity, are expected to contribute to the development of new therapeutic strategies.
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Affiliation(s)
- Jiawei Shi
- Department of Cardiology, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
- Key Laboratory for Biomedical Engineering of the Ministry of Education, College of Biomedical Engineering and Instrument Science, Zhejiang University, Hangzhou, China
| | - Weiwei Yin
- Department of Cardiology, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
- Zhejiang Provincial Key Laboratory of Cardio-Cerebral Vascular Detection Technology and Medicinal Effectiveness Appraisal, Zhejiang University, Hangzhou, China
| | - Wei Chen
- Department of Cardiology, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
- Key Laboratory for Biomedical Engineering of the Ministry of Education, College of Biomedical Engineering and Instrument Science, Zhejiang University, Hangzhou, China
- Department of Cell Biology, School of Medicine, Zhejiang University, Hangzhou, China
- Liangzhu Laboratory, Zhejiang University, Hangzhou, China
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6
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Wilhelm KB, Vissa A, Groves JT. Differential Roles of Kinetic On- and Off-Rates in T-Cell Receptor Signal Integration Revealed with a Modified Fab'-DNA Ligand. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.01.587588. [PMID: 38617215 PMCID: PMC11014569 DOI: 10.1101/2024.04.01.587588] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/16/2024]
Abstract
Antibody-derived T-cell receptor (TCR) agonists are commonly used to activate T cells. While antibodies can trigger TCRs regardless of clonotype, they bypass native T cell signal integration mechanisms that rely on monovalent, membrane-associated, and relatively weakly-binding ligand in the context of cellular adhesion. Commonly used antibodies and their derivatives bind much more strongly than native peptide-MHC (pMHC) ligands bind their cognate TCRs. Because ligand dwell time is a critical parameter that tightly correlates with physiological function of the TCR signaling system, there is a general need, both in research and therapeutics, for universal TCR ligands with controlled kinetic binding parameters. To this end, we have introduced point mutations into recombinantly expressed α-TCRβ H57 Fab to modulate the dwell time of monovalent Fab binding to TCR. When tethered to a supported lipid bilayer via DNA complementation, these monovalent Fab'-DNA ligands activate T cells with potencies well-correlated with their TCR binding dwell time. Single-molecule tracking studies in live T cells reveal that individual binding events between Fab'-DNA ligands and TCRs elicit local signaling responses closely resembling native pMHC. The unique combination of high on- and off-rate of the H57 R97L mutant enables direct observations of cooperative interplay between ligand binding and TCR-proximal condensation of the linker for activation of T cells (LAT), which is not readily visualized with pMHC. This work provides insights into how T cells integrate kinetic information from synthetic ligands and introduces a method to develop affinity panels for polyclonal T cells, such as cells from a human patient.
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Affiliation(s)
- Kiera B Wilhelm
- Department of Chemistry, University of California-Berkeley, Berkeley, CA, 93720
| | - Anand Vissa
- Department of Chemistry, University of California-Berkeley, Berkeley, CA, 93720
| | - Jay T Groves
- Department of Chemistry, University of California-Berkeley, Berkeley, CA, 93720
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7
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Bond A, Fiaz S, Rollins KR, Nario JEQ, Rosen SJ, Granados A, Wilson MZ, Morrissey MA. Prior Fc Receptor activation primes macrophages for increased sensitivity to IgG via long term and short term mechanisms. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.14.567059. [PMID: 38014172 PMCID: PMC10680729 DOI: 10.1101/2023.11.14.567059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
Macrophages measure the 'eat-me' signal IgG to identify targets for phagocytosis. We wondered if prior encounters with IgG influence macrophage appetite. IgG is recognized by the Fc Receptor. To temporally control Fc Receptor activation, we engineered an Fc Receptor that is activated by light-induced oligomerization of Cry2, triggering phagocytosis. Using this tool, we demonstrate that Fc Receptor activation primes macrophages to be more sensitive to IgG in future encounters. Macrophages that have previously experienced Fc Receptor activation eat more IgG-bound cancer cells. Increased phagocytosis occurs by two discrete mechanisms - a short- and long-term priming. Long term priming requires new protein synthesis and Erk activity. Short term priming does not require new protein synthesis and correlates with an increase in Fc Receptor mobility. Our work demonstrates that IgG primes macrophages for increased phagocytosis, suggesting that therapeutic antibodies may become more effective after initial priming doses.
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Affiliation(s)
- Annalise Bond
- Molecular Cellular and Developmental Biology Department, University of California, Santa Barbara, Santa Barbara CA
| | - Sareen Fiaz
- Molecular Cellular and Developmental Biology Department, University of California, Santa Barbara, Santa Barbara CA
| | - Kirstin R Rollins
- Molecular Cellular and Developmental Biology Department, University of California, Santa Barbara, Santa Barbara CA
| | - Jazz Elaiza Q Nario
- Molecular Cellular and Developmental Biology Department, University of California, Santa Barbara, Santa Barbara CA
| | - Samuel J Rosen
- Molecular Cellular and Developmental Biology Department, University of California, Santa Barbara, Santa Barbara CA
| | - Alyssa Granados
- Molecular Cellular and Developmental Biology Department, University of California, Santa Barbara, Santa Barbara CA
| | - Maxwell Z Wilson
- Molecular Cellular and Developmental Biology Department, University of California, Santa Barbara, Santa Barbara CA
| | - Meghan A Morrissey
- Molecular Cellular and Developmental Biology Department, University of California, Santa Barbara, Santa Barbara CA
- Lead contact
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8
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Ye Y, Morita S, Chang JJ, Buckley PM, Wilhelm KB, DiMaio D, Groves JT, Barrera FN. Allosteric inhibition of the T cell receptor by a designed membrane ligand. eLife 2023; 12:e82861. [PMID: 37796108 PMCID: PMC10554751 DOI: 10.7554/elife.82861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Accepted: 09/20/2023] [Indexed: 10/06/2023] Open
Abstract
The T cell receptor (TCR) is a complex molecular machine that directs the activation of T cells, allowing the immune system to fight pathogens and cancer cells. Despite decades of investigation, the molecular mechanism of TCR activation is still controversial. One of the leading activation hypotheses is the allosteric model. This model posits that binding of pMHC at the extracellular domain triggers a dynamic change in the transmembrane (TM) domain of the TCR subunits, which leads to signaling at the cytoplasmic side. We sought to test this hypothesis by creating a TM ligand for TCR. Previously we described a method to create a soluble peptide capable of inserting into membranes and binding to the TM domain of the receptor tyrosine kinase EphA2 (Alves et al., eLife, 2018). Here, we show that the approach is generalizable to complex membrane receptors, by designing a TM ligand for TCR. We observed that the designed peptide caused a reduction of Lck phosphorylation of TCR at the CD3ζ subunit in T cells. As a result, in the presence of this peptide inhibitor of TCR (PITCR), the proximal signaling cascade downstream of TCR activation was significantly dampened. Co-localization and co-immunoprecipitation in diisobutylene maleic acid (DIBMA) native nanodiscs confirmed that PITCR was able to bind to the TCR. AlphaFold-Multimer predicted that PITCR binds to the TM region of TCR, where it interacts with the two CD3ζ subunits. Our results additionally indicate that PITCR disrupts the allosteric changes in the compactness of the TM bundle that occur upon TCR activation, lending support to the allosteric TCR activation model. The TCR inhibition achieved by PITCR might be useful to treat inflammatory and autoimmune diseases and to prevent organ transplant rejection, as in these conditions aberrant activation of TCR contributes to disease.
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Affiliation(s)
- Yujie Ye
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee at KnoxvilleKnoxvilleUnited States
| | - Shumpei Morita
- Department of Chemistry, University of California, BerkeleyBerkeleyUnited States
| | - Justin J Chang
- Department of Genetics, Yale UniversityNew HavenUnited States
| | - Patrick M Buckley
- Department of Microbial Pathogenesis, Yale UniversityNew HavenUnited States
| | - Kiera B Wilhelm
- Department of Chemistry, University of California, BerkeleyBerkeleyUnited States
| | - Daniel DiMaio
- Department of Genetics, Yale UniversityNew HavenUnited States
| | - Jay T Groves
- Department of Chemistry, University of California, BerkeleyBerkeleyUnited States
- Institute for Digital Molecular Analytics and Science, Nanyang Technological UniversitySingaporeSingapore
| | - Francisco N Barrera
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee at KnoxvilleKnoxvilleUnited States
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9
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Morgan J, Lindsay AE. Modulation of antigen discrimination by duration of immune contacts in a kinetic proofreading model of T cell activation with extreme statistics. PLoS Comput Biol 2023; 19:e1011216. [PMID: 37647345 PMCID: PMC10497171 DOI: 10.1371/journal.pcbi.1011216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Revised: 09/12/2023] [Accepted: 08/05/2023] [Indexed: 09/01/2023] Open
Abstract
T cells form transient cell-to-cell contacts with antigen presenting cells (APCs) to facilitate surface interrogation by membrane bound T cell receptors (TCRs). Upon recognition of molecular signatures (antigen) of pathogen, T cells may initiate an adaptive immune response. The duration of the T cell/APC contact is observed to vary widely, yet it is unclear what constructive role, if any, such variations might play in immune signaling. Modeling efforts describing antigen discrimination often focus on steady-state approximations and do not account for the transient nature of cellular contacts. Within the framework of a kinetic proofreading (KP) mechanism, we develop a stochastic First Receptor Activation Model (FRAM) describing the likelihood that a productive immune signal is produced before the expiry of the contact. Through the use of extreme statistics, we characterize the probability that the first TCR triggering is induced by a rare agonist antigen and not by that of an abundant self-antigen. We show that defining positive immune outcomes as resilience to extreme statistics and sensitivity to rare events mitigates classic tradeoffs associated with KP. By choosing a sufficient number of KP steps, our model is able to yield single agonist sensitivity whilst remaining non-reactive to large populations of self antigen, even when self and agonist antigen are similar in dissociation rate to the TCR but differ largely in expression. Additionally, our model achieves high levels of accuracy even when agonist positive APCs encounters are rare. Finally, we discuss potential biological costs associated with high classification accuracy, particularly in challenging T cell environments.
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Affiliation(s)
- Jonathan Morgan
- Department of Applied and Computational Mathematics and Statistics, University of Notre Dame, South Bend, Indiana, United States of America
- Biophysics Graduate Program, University of Notre Dame, South Bend, Indiana, United States of America
| | - Alan E. Lindsay
- Department of Applied and Computational Mathematics and Statistics, University of Notre Dame, South Bend, Indiana, United States of America
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10
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Li L, Ji J, Song F, Hu J. Intercellular Receptor-ligand Binding: Effect of Protein-membrane Interaction. J Mol Biol 2023; 435:167787. [PMID: 35952805 DOI: 10.1016/j.jmb.2022.167787] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 08/03/2022] [Accepted: 08/04/2022] [Indexed: 02/04/2023]
Abstract
Gaining insights into the intercellular receptor-ligand binding is of great importance for understanding numerous physiological and pathological processes, and stimulating new strategies in drug design and discovery. In contrast to the in vitro protein interaction in solution, the anchored receptor and ligand molecules interact with membrane in situ, which affects the intercellular receptor-ligand binding. Here, we review theoretical, simulation and experimental works regarding the regulatory effects of protein-membrane interactions on intercellular receptor-ligand binding mainly from the following aspects: membrane fluctuations, membrane curvature, glycocalyx, and lipid raft. In addition, we discuss biomedical significances and possible research directions to advance the field and highlight the importance of understanding of coupling effects of these factors in pharmaceutical development.
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Affiliation(s)
- Long Li
- Kuang Yaming Honors School and Institute for Brain Sciences, Nanjing University, 210023 Nanjing, China; State Key Laboratory of Nonlinear Mechanics and Beijing Key Laboratory of Engineered Construction and Mechanobiology, Institute of Mechanics, Chinese Academy of Sciences, 100190 Beijing, China
| | - Jing Ji
- Key Laboratory of Biomechanics and Mechanobiology (Beihang University), Ministry of Education Beijing Advanced Innovation Center for Biomedical Engineering School of Biological Science and Medical Engineering, Beihang University, Beijing 100083, China.
| | - Fan Song
- State Key Laboratory of Nonlinear Mechanics and Beijing Key Laboratory of Engineered Construction and Mechanobiology, Institute of Mechanics, Chinese Academy of Sciences, 100190 Beijing, China; School of Engineering Science, University of Chinese Academy of Sciences, 100049 Beijing, China
| | - Jinglei Hu
- Kuang Yaming Honors School and Institute for Brain Sciences, Nanjing University, 210023 Nanjing, China.
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11
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Cao F, Taylor MJ. Visualization of Myddosome Assembly in Live Cells. Methods Mol Biol 2023; 2654:231-250. [PMID: 37106186 DOI: 10.1007/978-1-0716-3135-5_15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Abstract
The Myddosome is an oligomeric protein complex composed of MyD88 and members of IL-1 receptor-associated kinase (IRAK) family that transduce signals from Toll-like and IL-1 family receptors. The molecular dynamics of Myddosome formation and how the Myddosome organizes downstream signaling reactions provide insight into how TLR/IL-1Rs activate a decisive cellular response critical for the induction of inflammation. Supported lipid membranes formed on a continuous glass coverslip have been extensively used to study the molecular dynamics of receptor signaling. Here, we describe a protocol for the formation of IL-1-functionalized support lipid membrane that can be used to visualize the molecular dynamics of Myddosome formation and signaling in live cells.
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Affiliation(s)
- Fakun Cao
- Max Planck Institute for Infection Biology, Berlin, Germany
| | - Marcus J Taylor
- Max Planck Institute for Infection Biology, Berlin, Germany.
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12
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Sun Y, Sun J, Xiao M, Lai W, Li L, Fan C, Pei H. DNA origami-based artificial antigen-presenting cells for adoptive T cell therapy. SCIENCE ADVANCES 2022; 8:eadd1106. [PMID: 36459554 PMCID: PMC10936057 DOI: 10.1126/sciadv.add1106] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2022] [Accepted: 10/17/2022] [Indexed: 06/17/2023]
Abstract
Nanosized artificial antigen-presenting cells (aAPCs) with efficient signal presentation hold great promise for in vivo adoptive cell therapy. Here, we used DNA origami nanostructures as two-dimensional scaffolds to regulate the spatial presentation of activating ligands at nanoscale to construct high-effective aAPCs. The DNA origami-based aAPC comprises costimulatory ligands anti-CD28 antibody anchored at three vertices and T cell receptor (TCR) ligands peptide-major histocompatibility complex (pMHC) anchored at three edges with varying density. The DNA origami scaffold enables quantitative analysis of ligand-receptor interactions in T cell activation at the single-particle, single-molecule resolution. The pMHC-TCR-binding dwell time is increased from 9.9 to 12.1 s with increasing pMHC density, driving functional T cell responses. In addition, both in vitro and in vivo assays demonstrate that the optimized DNA origami-based aAPCs show effective tumor growth inhibiting capability in adoptive immunotherapy. These results provide important insights into the rational design of molecular vaccines for cancer immunotherapy.
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Affiliation(s)
- Yueyang Sun
- Shanghai Key Laboratory of Green Chemistry and Chemical Processes, School of Chemistry and Molecular Engineering, Shanghai Frontiers Science Center of Genome Editing and Cell Therapy, East China Normal University, 500 Dongchuan Road, Shanghai 200241, China
| | - Jiajia Sun
- Shanghai Key Laboratory of Green Chemistry and Chemical Processes, School of Chemistry and Molecular Engineering, Shanghai Frontiers Science Center of Genome Editing and Cell Therapy, East China Normal University, 500 Dongchuan Road, Shanghai 200241, China
| | - Mingshu Xiao
- Shanghai Key Laboratory of Green Chemistry and Chemical Processes, School of Chemistry and Molecular Engineering, Shanghai Frontiers Science Center of Genome Editing and Cell Therapy, East China Normal University, 500 Dongchuan Road, Shanghai 200241, China
| | - Wei Lai
- Shanghai Key Laboratory of Green Chemistry and Chemical Processes, School of Chemistry and Molecular Engineering, Shanghai Frontiers Science Center of Genome Editing and Cell Therapy, East China Normal University, 500 Dongchuan Road, Shanghai 200241, China
| | - Li Li
- Shanghai Key Laboratory of Green Chemistry and Chemical Processes, School of Chemistry and Molecular Engineering, Shanghai Frontiers Science Center of Genome Editing and Cell Therapy, East China Normal University, 500 Dongchuan Road, Shanghai 200241, China
| | - Chunhai Fan
- School of Chemistry and Chemical Engineering, and Institute of Molecular Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Hao Pei
- Shanghai Key Laboratory of Green Chemistry and Chemical Processes, School of Chemistry and Molecular Engineering, Shanghai Frontiers Science Center of Genome Editing and Cell Therapy, East China Normal University, 500 Dongchuan Road, Shanghai 200241, China
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13
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McAffee DB, O'Dair MK, Lin JJ, Low-Nam ST, Wilhelm KB, Kim S, Morita S, Groves JT. Discrete LAT condensates encode antigen information from single pMHC:TCR binding events. Nat Commun 2022; 13:7446. [PMID: 36460640 PMCID: PMC9718779 DOI: 10.1038/s41467-022-35093-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2022] [Accepted: 11/17/2022] [Indexed: 12/05/2022] Open
Abstract
LAT assembly into a two-dimensional protein condensate is a prominent feature of antigen discrimination by T cells. Here, we use single-molecule imaging techniques to resolve the spatial position and temporal duration of each pMHC:TCR molecular binding event while simultaneously monitoring LAT condensation at the membrane. An individual binding event is sufficient to trigger a LAT condensate, which is self-limiting, and neither its size nor lifetime is correlated with the duration of the originating pMHC:TCR binding event. Only the probability of the LAT condensate forming is related to the pMHC:TCR binding dwell time. LAT condenses abruptly, but after an extended delay from the originating binding event. A LAT mutation that facilitates phosphorylation at the PLC-γ1 recruitment site shortens the delay time to LAT condensation and alters T cell antigen specificity. These results identify a function for the LAT protein condensation phase transition in setting antigen discrimination thresholds in T cells.
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Affiliation(s)
- Darren B McAffee
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, 94720, USA
| | - Mark K O'Dair
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, 94720, USA
| | - Jenny J Lin
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, 94720, USA
| | - Shalini T Low-Nam
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, 94720, USA
| | - Kiera B Wilhelm
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, 94720, USA
| | - Sungi Kim
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, 94720, USA
| | - Shumpei Morita
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, 94720, USA
| | - Jay T Groves
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, 94720, USA.
- Institute for Digital Molecular Analytics and Science, Nanyang Technological University, 59 Nanyang Drive, Singapore, 636921, Singapore.
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14
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Britain DM, Town JP, Weiner OD. Progressive enhancement of kinetic proofreading in T cell antigen discrimination from receptor activation to DAG generation. eLife 2022; 11:e75263. [PMID: 36125261 PMCID: PMC9536835 DOI: 10.7554/elife.75263] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Accepted: 09/18/2022] [Indexed: 11/16/2022] Open
Abstract
T cells use kinetic proofreading to discriminate antigens by converting small changes in antigen-binding lifetime into large differences in cell activation, but where in the signaling cascade this computation is performed is unknown. Previously, we developed a light-gated immune receptor to probe the role of ligand kinetics in T cell antigen signaling. We found significant kinetic proofreading at the level of the signaling lipid diacylglycerol (DAG) but lacked the ability to determine where the multiple signaling steps required for kinetic discrimination originate in the upstream signaling cascade (Tiseher and Weiner, 2019). Here, we uncover where kinetic proofreading is executed by adapting our optogenetic system for robust activation of early signaling events. We find the strength of kinetic proofreading progressively increases from Zap70 recruitment to LAT clustering to downstream DAG generation. Leveraging the ability of our system to rapidly disengage ligand binding, we also measure slower reset rates for downstream signaling events. These data suggest a distributed kinetic proofreading mechanism, with proofreading steps both at the receptor and at slower resetting downstream signaling complexes that could help balance antigen sensitivity and discrimination.
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Affiliation(s)
- Derek M Britain
- Cardiovascular Research Institute and Department of Biochemistry and Biophysics, University of California, San FranciscoSan FranciscoUnited States
| | - Jason P Town
- Cardiovascular Research Institute and Department of Biochemistry and Biophysics, University of California, San FranciscoSan FranciscoUnited States
| | - Orion David Weiner
- Cardiovascular Research Institute and Department of Biochemistry and Biophysics, University of California, San FranciscoSan FranciscoUnited States
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15
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Li L, Hu J, Różycki B, Ji J, Song F. Interplay of receptor-ligand binding and lipid domain formation during cell adhesion. Front Mol Biosci 2022; 9:1019477. [PMID: 36203878 PMCID: PMC9531914 DOI: 10.3389/fmolb.2022.1019477] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Accepted: 09/05/2022] [Indexed: 11/20/2022] Open
Abstract
Cell adhesion involved in biological processes such as cell migration, immune responses, and cancer metastasis, is mediated by the specific binding of receptor and ligand proteins. Some of these proteins exhibit affinity for nanoscale lipid clusters in cell membranes. A key question is how these nanoscale lipid clusters influence and react to the receptor-ligand binding during cell adhesion. In this article, we review recent computational studies that shed new light on the interplay of the receptor-ligand binding and the formation of lipid domains in adhering membranes. These studies indicate that the receptor-ligand binding promotes coalescence of lipid clusters into mesoscale domains, which, in turn, enhances both the affinity and cooperativity of the receptor-ligand binding in cell-cell adhesion with mobile ligands. In contrast, in the case of cell-extracellular matrix adhesion with immobile ligands, the receptor-ligand binding and the lipid cluster coalescence can be correlated or anti-correlated, depending strongly on the ligand distribution. These findings deepen our understanding of correlations between cell adhesion and membrane heterogeneities.
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Affiliation(s)
- Long Li
- Kuang Yaming Honors School and Institute for Brain Sciences, Nanjing University, Nanjing, China
- State Key Laboratory of Nonlinear Mechanics and Beijing Key Laboratory of Engineered Construction and Mechanobiology, Institute of Mechanics, Chinese Academy of Sciences, Beijing, China
| | - Jinglei Hu
- Kuang Yaming Honors School and Institute for Brain Sciences, Nanjing University, Nanjing, China
- *Correspondence: Jinglei Hu, ; Bartosz Różycki, ; Jing Ji,
| | - Bartosz Różycki
- Institute of Physics, Polish Academy of Sciences, Warsaw, Poland
- *Correspondence: Jinglei Hu, ; Bartosz Różycki, ; Jing Ji,
| | - Jing Ji
- Key Laboratory of Biomechanics and Mechanobiology (Beihang University), Ministry of Education Beijing Advanced Innovation Center for Biomedical Engineering School of Biological Science and Medical Engineering, Beihang University, Beijing, China
- *Correspondence: Jinglei Hu, ; Bartosz Różycki, ; Jing Ji,
| | - Fan Song
- State Key Laboratory of Nonlinear Mechanics and Beijing Key Laboratory of Engineered Construction and Mechanobiology, Institute of Mechanics, Chinese Academy of Sciences, Beijing, China
- School of Engineering Science, University of Chinese Academy of Sciences, Beijing, China
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16
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Kanagy WK, Cleyrat C, Fazel M, Lucero SR, Bruchez MP, Lidke KA, Wilson BS, Lidke DS. Docking of Syk to FcεRI is enhanced by Lyn but limited in duration by SHIP1. Mol Biol Cell 2022; 33:ar89. [PMID: 35793126 PMCID: PMC9582627 DOI: 10.1091/mbc.e21-12-0603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
The high-affinity immunoglobulin E (IgE) receptor, FcεRI, is the primary immune receptor found on mast cells and basophils. Signal initiation is classically attributed to phosphorylation of FcεRI β− and γ-subunits by the Src family kinase (SFK) Lyn, followed by the recruitment and activation of the tyrosine kinase Syk. FcεRI signaling is tuned by the balance between Syk-driven positive signaling and the engagement of inhibitory molecules, including SHIP1. Here, we investigate the mechanistic contributions of Lyn, Syk, and SHIP1 to the formation of the FcεRI signalosome. Using Lyn-deficient RBL-2H3 mast cells, we found that another SFK can weakly monophosphorylate the γ-subunit, yet Syk still binds the incompletely phosphorylated immunoreceptor tyrosine-based activation motifs (ITAMs). Once recruited, Syk further enhances γ-phosphorylation to propagate signaling. In contrast, the loss of SHIP1 recruitment indicates that Lyn is required for phosphorylation of the β-subunit. We demonstrate two noncanonical Syk binding modes, trans γ-bridging and direct β-binding, that can support signaling when SHIP1 is absent. Using single particle tracking, we reveal a novel role of SHIP1 in regulating Syk activity, where the presence of SHIP1 in the signaling complex acts to increase the Syk:receptor off-rate. These data suggest that the composition and dynamics of the signalosome modulate immunoreceptor signaling activities.
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Affiliation(s)
- William K Kanagy
- Department of Pathology, University of New Mexico, Albuquerque, NM 87131
| | - Cédric Cleyrat
- Department of Pathology, University of New Mexico, Albuquerque, NM 87131.,Comprehensive Cancer Center, University of New Mexico, Albuquerque, NM 87131
| | - Mohamadreza Fazel
- Department of Physics, University of New Mexico, Albuquerque, NM 87131
| | - Shayna R Lucero
- Department of Pathology, University of New Mexico, Albuquerque, NM 87131
| | - Marcel P Bruchez
- Department of Biological Sciences and Department of Chemistry, Carnegie Mellon University, Pittsburgh, PA 15213
| | - Keith A Lidke
- Comprehensive Cancer Center, University of New Mexico, Albuquerque, NM 87131.,Department of Physics, University of New Mexico, Albuquerque, NM 87131
| | - Bridget S Wilson
- Department of Pathology, University of New Mexico, Albuquerque, NM 87131.,Comprehensive Cancer Center, University of New Mexico, Albuquerque, NM 87131
| | - Diane S Lidke
- Department of Pathology, University of New Mexico, Albuquerque, NM 87131.,Comprehensive Cancer Center, University of New Mexico, Albuquerque, NM 87131
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17
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Lin CW, Nocka LM, Stinger BL, DeGrandchamp JB, Lew LJN, Alvarez S, Phan HT, Kondo Y, Kuriyan J, Groves JT. A two-component protein condensate of the EGFR cytoplasmic tail and Grb2 regulates Ras activation by SOS at the membrane. Proc Natl Acad Sci U S A 2022; 119:e2122531119. [PMID: 35507881 PMCID: PMC9181613 DOI: 10.1073/pnas.2122531119] [Citation(s) in RCA: 37] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Accepted: 03/22/2022] [Indexed: 12/11/2022] Open
Abstract
We reconstitute a phosphotyrosine-mediated protein condensation phase transition of the ∼200 residue cytoplasmic tail of the epidermal growth factor receptor (EGFR) and the adaptor protein, Grb2, on a membrane surface. The phase transition depends on phosphorylation of the EGFR tail, which recruits Grb2, and crosslinking through a Grb2-Grb2 binding interface. The Grb2 Y160 residue plays a structurally critical role in the Grb2-Grb2 interaction, and phosphorylation or mutation of Y160 prevents EGFR:Grb2 condensation. By extending the reconstitution experiment to include the guanine nucleotide exchange factor, SOS, and its substrate Ras, we further find that the condensation state of the EGFR tail controls the ability of SOS, recruited via Grb2, to activate Ras. These results identify an EGFR:Grb2 protein condensation phase transition as a regulator of signal propagation from EGFR to the MAPK pathway.
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Affiliation(s)
- Chun-Wei Lin
- Department of Chemistry, University of California, Berkeley, CA 94720
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720
- California Institute for Quantitative Biosciences, University of California, Berkeley, CA 94720
| | - Laura M. Nocka
- Department of Chemistry, University of California, Berkeley, CA 94720
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720
- California Institute for Quantitative Biosciences, University of California, Berkeley, CA 94720
| | | | | | - L. J. Nugent Lew
- Department of Chemistry, University of California, Berkeley, CA 94720
| | - Steven Alvarez
- Department of Chemistry, University of California, Berkeley, CA 94720
| | - Henry T. Phan
- Department of Chemistry, University of California, Berkeley, CA 94720
| | - Yasushi Kondo
- Department of Chemistry, University of California, Berkeley, CA 94720
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720
- California Institute for Quantitative Biosciences, University of California, Berkeley, CA 94720
| | - John Kuriyan
- Department of Chemistry, University of California, Berkeley, CA 94720
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720
- California Institute for Quantitative Biosciences, University of California, Berkeley, CA 94720
- HHMI, Chevy Chase, MD 20815
| | - Jay T. Groves
- Department of Chemistry, University of California, Berkeley, CA 94720
- Division of Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, CA 94720
- Institute for Digital Molecular Analytics and Science, Nanyang Technological University, 639798 Singapore
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18
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Brameshuber M, Klotzsch E, Ponjavic A, Sezgin E. Understanding immune signaling using advanced imaging techniques. Biochem Soc Trans 2022; 50:853-866. [PMID: 35343569 PMCID: PMC9162467 DOI: 10.1042/bst20210479] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 03/07/2022] [Accepted: 03/08/2022] [Indexed: 12/13/2022]
Abstract
Advanced imaging is key for visualizing the spatiotemporal regulation of immune signaling which is a complex process involving multiple players tightly regulated in space and time. Imaging techniques vary in their spatial resolution, spanning from nanometers to micrometers, and in their temporal resolution, ranging from microseconds to hours. In this review, we summarize state-of-the-art imaging methodologies and provide recent examples on how they helped to unravel the mysteries of immune signaling. Finally, we discuss the limitations of current technologies and share our insights on how to overcome these limitations to visualize immune signaling with unprecedented fidelity.
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Affiliation(s)
- Mario Brameshuber
- Institute of Applied Physics – Biophysics, TU Wien, 1040 Vienna, Austria
| | - Enrico Klotzsch
- Humboldt-Universität zu Berlin, Institut für Biophysik, Experimentelle Biophysik Mechanobiologie, Sitz Invalidenstrasse 42, 10115 Berlin, Germany
| | - Aleks Ponjavic
- School of Physics and Astronomy, University of Leeds, Woodhouse Lane, Leeds LS2 9JT, U.K
- School of Food Science and Nutrition, University of Leeds, Woodhouse Lane, Leeds LS2 9JT, U.K
| | - Erdinc Sezgin
- Science for Life Laboratory, Department of Women's and Children's Health, Karolinska Institutet, 17165 Solna, Sweden
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19
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Banerjee S, Nara R, Chakraborty S, Chowdhury D, Haldar S. Integrin Regulated Autoimmune Disorders: Understanding the Role of Mechanical Force in Autoimmunity. Front Cell Dev Biol 2022; 10:852878. [PMID: 35372360 PMCID: PMC8971850 DOI: 10.3389/fcell.2022.852878] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Accepted: 02/08/2022] [Indexed: 11/13/2022] Open
Abstract
The pathophysiology of autoimmune disorders is multifactorial, where immune cell migration, adhesion, and lymphocyte activation play crucial roles in its progression. These immune processes are majorly regulated by adhesion molecules at cell–extracellular matrix (ECM) and cell–cell junctions. Integrin, a transmembrane focal adhesion protein, plays an indispensable role in these immune cell mechanisms. Notably, integrin is regulated by mechanical force and exhibit bidirectional force transmission from both the ECM and cytosol, regulating the immune processes. Recently, integrin mechanosensitivity has been reported in different immune cell processes; however, the underlying mechanics of these integrin-mediated mechanical processes in autoimmunity still remains elusive. In this review, we have discussed how integrin-mediated mechanotransduction could be a linchpin factor in the causation and progression of autoimmune disorders. We have provided an insight into how tissue stiffness exhibits a positive correlation with the autoimmune diseases’ prevalence. This provides a plausible connection between mechanical load and autoimmunity. Overall, gaining insight into the role of mechanical force in diverse immune cell processes and their dysregulation during autoimmune disorders will open a new horizon to understand this physiological anomaly.
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20
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Nieves DJ, Pandzic E, Gunasinghe SD, Goyette J, Owen DM, Justin Gooding J, Gaus K. The T cell receptor displays lateral signal propagation involving non-engaged receptors. NANOSCALE 2022; 14:3513-3526. [PMID: 35171177 DOI: 10.1039/d1nr05855j] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
T cells are highly sensitive to low levels of antigen, but how this sensitivity is achieved is currently unknown. Here, we imaged proximal TCR-CD3 signal propagation with single molecule localization microscopy (SMLM) in T cells activated with nanoscale clusters of TCR stimuli. We observed the formation of large TCR-CD3 clusters that exceeded the area of the ligand clusters, and required multivalent interactions facilitated by TCR-CD3 phosphorylation for assembly. Within these clustered TCR-CD3 domains, TCR-CD3 signaling spread laterally for ∼500 nm, far beyond the activating site, via non-engaged receptors. Local receptor density determined the functional cooperativity between engaged and non-engaged receptors, but lateral signal propagation was not influenced by the genetic deletion of ZAP70. Taken together, our data demonstrates that clustered ligands induced the clustering of non-ligated TCR-CD3 into domains that cooperatively facilitate lateral signal propagation.
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Affiliation(s)
- Daniel J Nieves
- EMBL Australia Node in Single Molecule Science, School of Medical Sciences and the ARC Centre of Excellence in Advanced Molecular Imaging, University of New South Wales, Sydney, Australia
- Institute of Immunology and Immunotherapy, School of Mathematics, and Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham, Birmingham, UK.
| | - Elvis Pandzic
- Katharina Gaus Light Microscopy Facility, Mark Wainwright Analytical Centre, University of New South Wales, Sydney, Australia
| | - Sachith D Gunasinghe
- EMBL Australia Node in Single Molecule Science, School of Medical Sciences and the ARC Centre of Excellence in Advanced Molecular Imaging, University of New South Wales, Sydney, Australia
| | - Jesse Goyette
- EMBL Australia Node in Single Molecule Science, School of Medical Sciences and the ARC Centre of Excellence in Advanced Molecular Imaging, University of New South Wales, Sydney, Australia
| | - Dylan M Owen
- Institute of Immunology and Immunotherapy, School of Mathematics, and Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham, Birmingham, UK.
| | - J Justin Gooding
- School of Chemistry and Australian Centre for NanoMedicine, University of New South Wales, Sydney, Australia
| | - Katharina Gaus
- EMBL Australia Node in Single Molecule Science, School of Medical Sciences and the ARC Centre of Excellence in Advanced Molecular Imaging, University of New South Wales, Sydney, Australia
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21
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Dam T, Chouliara M, Junghans V, Jönsson P. Supported Lipid Bilayers and the Study of Two-Dimensional Binding Kinetics. Front Mol Biosci 2022; 9:833123. [PMID: 35252352 PMCID: PMC8896763 DOI: 10.3389/fmolb.2022.833123] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Accepted: 01/27/2022] [Indexed: 11/13/2022] Open
Abstract
Binding between protein molecules on contacting cells is essential in initiating and regulating several key biological processes. In contrast to interactions between molecules in solution, these events are restricted to the two-dimensional (2D) plane of the meeting cell surfaces. However, converting between the more commonly available binding kinetics measured in solution and the so-called 2D binding kinetics has proven a complicated task since for the latter several factors other than the protein-protein interaction per se have an impact. A few important examples of these are: protein density, membrane fluctuations, force on the bond and the use of auxiliary binding molecules. The development of model membranes, and in particular supported lipid bilayers (SLBs), has made it possible to simplify the studied contact to analyze these effects and to measure 2D binding kinetics of individual protein-protein interactions. We will in this review give an overview of, and discuss, how different SLB systems have been used for this and compare different methods to measure binding kinetics in cell-SLB contacts. Typically, the SLB is functionalized with fluorescently labelled ligands whose interaction with the corresponding receptor on a binding cell can be detected. This interaction can either be studied 1) by an accumulation of ligands in the cell-SLB contact, whose magnitude depends on the density of the proteins and binding affinity of the interaction, or 2) by tracking single ligands in the SLB, which upon interaction with a receptor result in a change of motion of the diffusing ligand. The advantages and disadvantages of other methods measuring 2D binding kinetics will also be discussed and compared to the fluorescence-based methods. Although binding kinetic measurements in cell-SLB contacts have provided novel information on how ligands interact with receptors in vivo the number of these measurements is still limited. This is influenced by the complexity of the system as well as the required experimental time. Moreover, the outcome can vary significantly between studies, highlighting the necessity for continued development of methods to study 2D binding kinetics with higher precision and ease.
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Affiliation(s)
- Tommy Dam
- Department of Chemistry, Lund University, Lund, Sweden
| | | | - Victoria Junghans
- Nuffield Department of Medicine, CAMS Oxford Institute, University of Oxford, Oxford, United Kingdom
| | - Peter Jönsson
- Department of Chemistry, Lund University, Lund, Sweden
- *Correspondence: Peter Jönsson,
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22
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Farrell MV, Nunez AC, Yang Z, Pérez-Ferreros P, Gaus K, Goyette J. Protein-PAINT: Superresolution microscopy with signaling proteins. Sci Signal 2022; 15:eabg9782. [PMID: 35104163 DOI: 10.1126/scisignal.abg9782] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Superresolution techniques have advanced our understanding of complex cellular structures and processes but require the attachment of fluorophores to targets through tags or antibodies, which can be bulky and result in underlabeling. To overcome these limitations, we developed a technique to visualize the nanoscale binding locations of signaling proteins by taking advantage of their native interaction domains. Here, we demonstrated that pPAINT (protein point accumulation in nanoscale topography) is a new, single-molecule localization microscopy (SMLM) technique and used it to investigate T cell signaling by visualizing the Src homology 2 (SH2) domain, which is common in signaling molecules. When SH2 domain-containing proteins relocate to the plasma membrane, the domains selectively, transiently, and reversibly bind to preferred phosphorylated tyrosine residues on receptors. This transient binding yields the stochastic blinking events necessary for SMLM when observed with total internal reflection microscopy and enables quantification of binding coefficients in intact cells. We used pPAINT to reveal the binding sites of several T cell receptor-proximal signaling molecules, including Zap70, PI3K, Grb2, Syk, Eat2, and SHP2, and showed that the probes could be multiplexed. We showed that the binding half-life of the tandem SH2 domain of PI3K correlated with binding site cluster size at the immunological synapses of T cells, but that longer binding lifetimes were associated with smaller clusters for the monovalent SH2 domain of Eat2. These results demonstrate the potential of pPAINT for investigating phosphotyrosine-mediated signaling processes at the plasma membrane.
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Affiliation(s)
- Megan V Farrell
- EMBL Australia Node in Single Molecule Science, School of Medical Sciences, University of New South Wales, Sydney, Australia
| | - Andrea C Nunez
- EMBL Australia Node in Single Molecule Science, School of Medical Sciences, University of New South Wales, Sydney, Australia
| | - Zhengmin Yang
- EMBL Australia Node in Single Molecule Science, School of Medical Sciences, University of New South Wales, Sydney, Australia
| | - Pablo Pérez-Ferreros
- EMBL Australia Node in Single Molecule Science, School of Medical Sciences, University of New South Wales, Sydney, Australia
| | - Katharina Gaus
- EMBL Australia Node in Single Molecule Science, School of Medical Sciences, University of New South Wales, Sydney, Australia
| | - Jesse Goyette
- EMBL Australia Node in Single Molecule Science, School of Medical Sciences, University of New South Wales, Sydney, Australia
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23
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Li L, Gao J, Shao Y, Song F, Hu J. Tuning cell adhesion on supported lipid bilayers via nanoscale geometry. SOFT MATTER 2021; 17:10376-10382. [PMID: 34747961 DOI: 10.1039/d1sm01407b] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The cell-supported lipid bilayer (SLB) adhesion system has been widely used as the model system to study the receptor-ligand interactions that occur at the membrane interface. The ligand-functionalized SLBs are deposited either directly on solids or on polymer cushions. An important question that arises is whether the geometry of the SLB affects the binding of cell adhesion receptors to the ligands. By using a mesoscopic mechanical model and Monte Carlo simulations, we have investigated the adhesion of a fluid membrane to a corrugated or egg-carton shaped SLB. We find that the nanoscale geometry of the SLB strongly affects the receptor-ligand binding. This effect results from the fact that the adhering membrane bends according to the SLB geometry in order for the adhesion receptors to bind ligands. The membrane bending couples with spatial distribution of the receptor-ligand complexes and membrane thermal undulations. Our results demonstrate that cell adhesion to SLBs can be controlled by tuning the nanoscale geometry of the SLB, and may have profound implications for future development of tissue engineering and regenerative medicine.
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Affiliation(s)
- Long Li
- State Key Laboratory of Nonlinear Mechanics and Beijing Key Laboratory of Engineered Construction and Mechanobiology, Institute of Mechanics, Chinese Academy of Sciences, Beijing, China.
| | - Jie Gao
- Kuang Yaming Honors School and Institute for Brain Sciences, Nanjing University, Nanjing, China.
| | - Yingfeng Shao
- State Key Laboratory of Nonlinear Mechanics and Beijing Key Laboratory of Engineered Construction and Mechanobiology, Institute of Mechanics, Chinese Academy of Sciences, Beijing, China.
| | - Fan Song
- State Key Laboratory of Nonlinear Mechanics and Beijing Key Laboratory of Engineered Construction and Mechanobiology, Institute of Mechanics, Chinese Academy of Sciences, Beijing, China.
- School of Engineering Science, University of Chinese Academy of Sciences, Beijing, China
| | - Jinglei Hu
- Kuang Yaming Honors School and Institute for Brain Sciences, Nanjing University, Nanjing, China.
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24
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Chouliara M, Junghans V, Dam T, Santos AM, Davis SJ, Jönsson P. Single-cell measurements of two-dimensional binding affinity across cell contacts. Biophys J 2021; 120:5032-5040. [PMID: 34653390 PMCID: PMC8633712 DOI: 10.1016/j.bpj.2021.10.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Revised: 09/21/2021] [Accepted: 10/08/2021] [Indexed: 12/21/2022] Open
Abstract
The two-dimensional (2D) affinity between protein molecules across contacting cells is a key parameter regulating and initiating several cellular processes. However, measuring 2D affinity can be challenging, and experimental data are limited. In addition, the obtained 2D affinities are typically averaged over the cell population. We here present a method to measure 2D affinity on single cells binding to polyhistidine-tagged fluorescent ligands anchored to a supported lipid bilayer (SLB). By decreasing the density of ligands in the SLB using imidazole, a new steady-state accumulation in the contact is obtained, and from this change, both the 2D affinity and the number of receptors on the cell can be determined. The method was validated on an SLB containing rat CD2 binding to the rat CD48 mutant T92A expressed on Jurkat T cells. The addition of imidazole did not influence the average 2D affinity (1/Kd), and the spread in affinities within the cell population was low, Kd = 4.9 ± 0.9 molecules/μm2 (mean ± SD), despite an order of magnitude spread in ligand accumulation because of differences in receptor density. It was also found that cell contact size increased both with ligand density and with the number of receptors per cell but that the contact size stayed approximately constant when lowering the ligand density, above a density of around 10 rat CD2 molecules/μm2, after the contact first had formed, indicative of a heterogeneous process. In summary, this method not only allows for single-cell affinities to be measured, but it can also reduce measurement and analysis time and improve measurement accuracy. Because of the low spread in 2D Kd within the cell population, the analysis can further be restricted to the cells showing the strongest binding, paving the way for using this method to study weak binding events.
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Affiliation(s)
| | - Victoria Junghans
- Department of Chemistry, Lund University, Lund, Sweden; Radcliffe Department of Medicine and Medical Research Council Human Immunology Unit, John Radcliffe Hospital, University of Oxford, Oxford, United Kingdom
| | - Tommy Dam
- Department of Chemistry, Lund University, Lund, Sweden
| | - Ana Mafalda Santos
- Radcliffe Department of Medicine and Medical Research Council Human Immunology Unit, John Radcliffe Hospital, University of Oxford, Oxford, United Kingdom
| | - Simon J Davis
- Radcliffe Department of Medicine and Medical Research Council Human Immunology Unit, John Radcliffe Hospital, University of Oxford, Oxford, United Kingdom
| | - Peter Jönsson
- Department of Chemistry, Lund University, Lund, Sweden.
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25
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DNA origami patterning of synthetic T cell receptors reveals spatial control of the sensitivity and kinetics of signal activation. Proc Natl Acad Sci U S A 2021; 118:2109057118. [PMID: 34588308 DOI: 10.1073/pnas.2109057118] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/19/2021] [Indexed: 12/27/2022] Open
Abstract
Receptor clustering plays a key role in triggering cellular activation, but the relationship between the spatial configuration of clusters and the elicitation of downstream intracellular signals remains poorly understood. We developed a DNA-origami-based system that is easily adaptable to other cellular systems and enables rich interrogation of responses to a variety of spatially defined inputs. Using a chimeric antigen receptor (CAR) T cell model system with relevance to cancer therapy, we studied signaling dynamics at single-cell resolution. We found that the spatial arrangement of receptors determines the ligand density threshold for triggering and encodes the temporal kinetics of signaling activities. We also showed that signaling sensitivity of a small cluster of high-affinity ligands is enhanced when surrounded by nonstimulating low-affinity ligands. Our results suggest that cells measure spatial arrangements of ligands, translate that information into distinct signaling dynamics, and provide insights into engineering immunotherapies.
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26
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Trapping or slowing the diffusion of T cell receptors at close contacts initiates T cell signaling. Proc Natl Acad Sci U S A 2021; 118:2024250118. [PMID: 34526387 PMCID: PMC8488633 DOI: 10.1073/pnas.2024250118] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/05/2021] [Indexed: 12/27/2022] Open
Abstract
T cell activation is initiated by T cell receptor (TCR) phosphorylation. This requires the local depletion of large receptor-type phosphatases from "close contacts" formed when T cells interact with surfaces presenting agonistic TCR ligands, but exactly how the ligands potentiate signaling is unclear. It has been proposed that TCR ligands could enhance receptor phosphorylation and signaling just by holding TCRs in phosphatase-depleted close contacts, but this has not been directly tested. We devised simple methods to move the TCR in and out of close contacts formed by T cells interacting with supported lipid bilayers (SLBs) and to slow the receptor's diffusion in the contacts, using a series of anti-CD3ε Fab- and ligand-based adducts of the receptor. TCRs engaging a Fab extended with the large extracellular region of CD45 were excluded from contacts and produced no signaling. Conversely, allowing the extended Fab to become tethered to the SLB trapped the TCR in the close contacts, leading to very strong signaling. Importantly, attaching untethered anti-CD3ε Fab or peptide/MHC ligands, each of which were largely inactive in solution but both of which reduced TCR diffusion in close contacts approximately fivefold, also initiated signaling during cell/SLB contact. Our findings indicate that holding TCRs in close contacts or simply slowing their diffusion in phosphatase-depleted regions of the cell surface suffices to initiate signaling, effects we could reproduce in single-particle stochastic simulations. Our study shows that the TCR is preconfigured for signaling in a way that allows it to be triggered by ligands acting simply as receptor "traps."
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27
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Wilhelm KB, Morita S, McAffee DB, Kim S, O'Dair MK, Groves JT. Height, but not binding epitope, affects the potency of synthetic TCR agonists. Biophys J 2021; 120:3869-3880. [PMID: 34453921 PMCID: PMC8511163 DOI: 10.1016/j.bpj.2021.08.027] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 08/16/2021] [Accepted: 08/20/2021] [Indexed: 12/27/2022] Open
Abstract
Under physiological conditions, peptide-major histocompatibility complex (pMHC) molecules can trigger T cell receptors (TCRs) as monovalent ligands that are sparsely distributed on the plasma membrane of an antigen-presenting cell. TCRs can also be triggered by artificial clustering, such as with pMHC tetramers or antibodies; however, these strategies circumvent many of the natural ligand discrimination mechanisms of the T cell and can elicit nonphysiological signaling activity. We have recently introduced a synthetic TCR agonist composed of an anti-TCRβ Fab′ antibody fragment covalently bound to a DNA oligonucleotide, which serves as a membrane anchor. This Fab′-DNA ligand efficiently triggers TCR as a monomer when membrane associated and exhibits a potency and activation profile resembling agonist pMHC. In this report, we explore the geometric requirements for efficient TCR triggering and cellular activation by Fab′-DNA ligands. We find that T cells are insensitive to the ligand binding epitope on the TCR complex but that length of the DNA tether is important. Increasing, the intermembrane distance spanned by Fab′-DNA:TCR complexes decreases TCR triggering efficiency and T cell activation potency, consistent with the kinetic-segregation model of TCR triggering. These results establish design parameters for constructing synthetic TCR agonists that are able to activate polyclonal T cell populations, such as T cells from a human patient, in a similar manner as the native pMHC ligand.
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Affiliation(s)
- Kiera B Wilhelm
- Department of Chemistry, University of California, Berkeley, California
| | - Shumpei Morita
- Department of Chemistry, University of California, Berkeley, California
| | - Darren B McAffee
- Department of Chemistry, University of California, Berkeley, California
| | - Sungi Kim
- Department of Chemistry, University of California, Berkeley, California
| | - Mark K O'Dair
- Department of Chemistry, University of California, Berkeley, California
| | - Jay T Groves
- Department of Chemistry, University of California, Berkeley, California.
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28
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Laursen T, Lam HYM, Sørensen KK, Tian P, Hansen CC, Groves JT, Jensen KJ, Christensen SM. Membrane anchoring facilitates colocalization of enzymes in plant cytochrome P450 redox systems. Commun Biol 2021; 4:1057. [PMID: 34504298 PMCID: PMC8429664 DOI: 10.1038/s42003-021-02604-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2021] [Accepted: 08/25/2021] [Indexed: 01/03/2023] Open
Abstract
Plant metabolism depends on cascade reactions mediated by dynamic enzyme assemblies known as metabolons. In this context, the cytochrome P450 (P450) superfamily catalyze key reactions underpinning the unique diversity of bioactive compounds. In contrast to their soluble bacterial counterparts, eukaryotic P450s are anchored to the endoplasmic reticulum membrane and serve as metabolon nucleation sites. Hence, membrane anchoring appears to play a pivotal role in the evolution of complex biosynthetic pathways. Here, a model membrane assay enabled characterization of membrane anchor dynamics by single molecule microscopy. As a model system, we reconstituted the membrane anchor of cytochrome P450 oxidoreductase (POR), the ubiquitous electron donor to all microsomal P450s. The transmembrane segment in the membrane anchor of POR is relatively conserved, corroborating its functional importance. We observe dynamic colocalization of the POR anchors in our assay suggesting that membrane anchoring might promote intermolecular interactions and in this way impact assembly of metabolic multienzyme complexes.
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Affiliation(s)
- Tomas Laursen
- Department of Plant and Environmental Sciences, University of Copenhagen, Copenhagen, Denmark
| | | | | | | | - Cecilie Cetti Hansen
- Department of Plant and Environmental Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jay T Groves
- Department of Chemistry, University of California, Berkeley, CA, USA
| | | | - Sune M Christensen
- Department of Chemistry, University of California, Berkeley, CA, USA. .,Enzyme Research, Lyngby, Denmark.
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29
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Abstract
T cells experience complex temporal patterns of stimulus via receptor-ligand-binding interactions with surrounding cells. From these temporal patterns, T cells are able to pick out antigenic signals while establishing self-tolerance. Although features such as duration of antigen binding have been examined, our understanding of how T cells interpret signals with different frequencies or temporal stimulation patterns is relatively unexplored. We engineered T cells to respond to light as a stimulus by building an optogenetically controlled chimeric antigen receptor (optoCAR). We discovered that T cells respond to minute-scale oscillations of activation signal by stimulating optoCAR T cells with tunable pulse trains of light. Systematically scanning signal oscillation period from 1 to 150 min revealed that expression of CD69, a T cell activation marker, reached a local minimum at a period of ∼25 min (corresponding to 5 to 15 min pulse widths). A combination of inhibitors and genetic knockouts suggest that this frequency filtering mechanism lies downstream of the Erk signaling branch of the T cell response network and may involve a negative feedback loop that diminishes Erk activity. The timescale of CD69 filtering corresponds with the duration of T cell encounters with self-peptide-presenting APCs observed via intravital imaging in mice, indicating a potential functional role for temporal filtering in vivo. This study illustrates that the T cell signaling machinery is tuned to temporally filter and interpret time-variant input signals in discriminatory ways.
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30
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Saed B, Munaweera R, Anderson J, O'Neill WD, Hu YS. Rapid statistical discrimination of fluorescence images of T cell receptors on immobilizing surfaces with different coating conditions. Sci Rep 2021; 11:15488. [PMID: 34326382 PMCID: PMC8322097 DOI: 10.1038/s41598-021-94730-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Accepted: 07/15/2021] [Indexed: 11/24/2022] Open
Abstract
The spatial organization of T cell receptors (TCRs) correlates with membrane-associated signal amplification, dispersion, and regulation during T cell activation. Despite its potential clinical importance, quantitative analysis of the spatial arrangement of TCRs from standard fluorescence images remains difficult. Here, we report Statistical Classification Analyses of Membrane Protein Images or SCAMPI as a technique capable of analyzing the spatial arrangement of TCRs on the plasma membrane of T cells. We leveraged medical image analysis techniques that utilize pixel-based values. We transformed grayscale pixel values from fluorescence images of TCRs into estimated model parameters of partial differential equations. The estimated model parameters enabled an accurate classification using linear discrimination techniques, including Fisher Linear Discriminant (FLD) and Logistic Regression (LR). In a proof-of-principle study, we modeled and discriminated images of fluorescently tagged TCRs from Jurkat T cells on uncoated cover glass surfaces (Null) or coated cover glass surfaces with either positively charged poly-L-lysine (PLL) or TCR cross-linking anti-CD3 antibodies (OKT3). Using 80 training images and 20 test images per class, our statistical technique achieved 85% discrimination accuracy for both OKT3 versus PLL and OKT3 versus Null conditions. The run time of image data download, model construction, and image discrimination was 21.89 s on a laptop computer, comprised of 20.43 s for image data download, 1.30 s on the FLD-SCAMPI analysis, and 0.16 s on the LR-SCAMPI analysis. SCAMPI represents an alternative approach to morphology-based qualifications for discriminating complex patterns of membrane proteins conditioned on a small sample size and fast runtime. The technique paves pathways to characterize various physiological and pathological conditions using the spatial organization of TCRs from patient T cells.
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Affiliation(s)
- Badeia Saed
- Department of Chemistry, College of Liberal Arts and Sciences, University of Illinois at Chicago, Chicago, IL, 60607, USA
| | - Rangika Munaweera
- Department of Chemistry, College of Liberal Arts and Sciences, University of Illinois at Chicago, Chicago, IL, 60607, USA
| | - Jesse Anderson
- Department of Chemical Engineering, University of Illinois at Chicago, Chicago, IL, 60607, USA
| | - William D O'Neill
- Department of Bioengineering, Colleges of Engineering and Medicine, University of Illinois at Chicago, Chicago, IL, 60607, USA.
| | - Ying S Hu
- Department of Chemistry, College of Liberal Arts and Sciences, University of Illinois at Chicago, Chicago, IL, 60607, USA.
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31
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Lanz AL, Masi G, Porciello N, Cohnen A, Cipria D, Prakaash D, Bálint Š, Raggiaschi R, Galgano D, Cole DK, Lepore M, Dushek O, Dustin ML, Sansom MSP, Kalli AC, Acuto O. Allosteric activation of T cell antigen receptor signaling by quaternary structure relaxation. Cell Rep 2021; 36:109375. [PMID: 34260912 PMCID: PMC8293630 DOI: 10.1016/j.celrep.2021.109375] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Revised: 05/05/2021] [Accepted: 06/18/2021] [Indexed: 01/05/2023] Open
Abstract
The mechanism of T cell antigen receptor (TCR-CD3) signaling remains elusive. Here, we identify mutations in the transmembrane region of TCRβ or CD3ζ that augment peptide T cell antigen receptor (pMHC)-induced signaling not explicable by enhanced ligand binding, lateral diffusion, clustering, or co-receptor function. Using a biochemical assay and molecular dynamics simulation, we demonstrate that the gain-of-function mutations loosen the interaction between TCRαβ and CD3ζ. Similar to the activating mutations, pMHC binding reduces TCRαβ cohesion with CD3ζ. This event occurs prior to CD3ζ phosphorylation and at 0°C. Moreover, we demonstrate that soluble monovalent pMHC alone induces signaling and reduces TCRαβ cohesion with CD3ζ in membrane-bound or solubilised TCR-CD3. Our data provide compelling evidence that pMHC binding suffices to activate allosteric changes propagating from TCRαβ to the CD3 subunits, reconfiguring interchain transmembrane region interactions. These dynamic modifications could change the arrangement of TCR-CD3 boundary lipids to license CD3ζ phosphorylation and initiate signal propagation. Mutations in TCRβ and CD3ζ TMRs that reduce their interaction augment signaling pMHC and anti-CD3 binding to TCR-CD3 induce similar quaternary structure relaxation Soluble monovalent pMHC alone signals and reduces TCRαβ cohesion with CD3ζ Allosteric changes in TCR-CD3 dynamics instigate T cell activation
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Affiliation(s)
- Anna-Lisa Lanz
- T-cell signalling laboratory, Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, UK
| | - Giulia Masi
- T-cell signalling laboratory, Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, UK
| | - Nicla Porciello
- T-cell signalling laboratory, Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, UK
| | - André Cohnen
- T-cell signalling laboratory, Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, UK
| | - Deborah Cipria
- T-cell signalling laboratory, Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, UK
| | - Dheeraj Prakaash
- Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds LS2 9JT, UK
| | - Štefan Bálint
- Kennedy Institute of Rheumatology, University of Oxford, Oxford OX3 7FY, UK
| | - Roberto Raggiaschi
- T-cell signalling laboratory, Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, UK
| | - Donatella Galgano
- T-cell signalling laboratory, Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, UK
| | - David K Cole
- Division Infection & Immunity, Cardiff University, Cardiff CF14 4XN, UK; Immunocore Ltd., Abingdon OX14 4RY, UK
| | | | - Omer Dushek
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, UK
| | - Michael L Dustin
- Kennedy Institute of Rheumatology, University of Oxford, Oxford OX3 7FY, UK
| | - Mark S P Sansom
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK.
| | - Antreas C Kalli
- Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds LS2 9JT, UK; Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK.
| | - Oreste Acuto
- T-cell signalling laboratory, Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, UK.
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32
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Nanopore-mediated protein delivery enabling three-color single-molecule tracking in living cells. Proc Natl Acad Sci U S A 2021; 118:2012229118. [PMID: 33495347 DOI: 10.1073/pnas.2012229118] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Multicolor single-molecule tracking (SMT) provides a powerful tool to mechanistically probe molecular interactions in living cells. However, because of the limitations in the optical and chemical properties of currently available fluorophores and the multiprotein labeling strategies, intracellular multicolor SMT remains challenging for general research studies. Here, we introduce a practical method employing a nanopore-electroporation (NanoEP) technique to deliver multiple organic dye-labeled proteins into living cells for imaging. It can be easily expanded to three channels in commercial microscopes or be combined with other in situ labeling methods. Utilizing NanoEP, we demonstrate three-color SMT for both cytosolic and membrane proteins. Specifically, we simultaneously monitored single-molecule events downstream of EGFR signaling pathways in living cells. The results provide detailed resolution of the spatial localization and dynamics of Grb2 and SOS recruitment to activated EGFR along with the resultant Ras activation.
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33
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Li L, Wang X, Wu H, Shao Y, Wu H, Song F. Interplay Between Receptor-Ligand Binding and Lipid Domain Formation Depends on the Mobility of Ligands in Cell-Substrate Adhesion. Front Mol Biosci 2021; 8:655662. [PMID: 33987204 PMCID: PMC8112205 DOI: 10.3389/fmolb.2021.655662] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Accepted: 02/17/2021] [Indexed: 12/20/2022] Open
Abstract
Cell-cell adhesion and the adhesion of cells to extracellular matrix are mediated by the specific binding of receptors on the cell membrane to their cognate ligands on the opposing surface. The adhesion receptors can exhibit affinity for nanoscale lipid clusters that form in the cell membrane. Experimental studies of such adhesion systems often involve a cell adhering either to a solid surface with immobile ligands or a supported lipid bilayer with mobile ligands. A central question in these cell-substrate adhesions is how the mobility of the ligands physically affects their binding to the adhesion receptors and thereby the behavior of the nanoscale lipid clusters associated with the receptors. Using a statistical mechanical model and Monte Carlo simulations for the adhesion of cells to substrates with ligands, we find that, for mobile ligands, binding to adhesion receptors can promote the formation of mesoscale lipid domains, which in turn enhances the receptor-ligand binding. However, in the case of immobile ligands, the receptor-ligand binding and the tendency for the nanoscale lipid clusters to further coalesce depend on the distribution of the ligands on the substrate. Our findings help to explain why different adhesion experiments for identifying the interplay between receptor-ligand binding and heterogeneities in cell membranes led to contradictory results.
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Affiliation(s)
- Long Li
- State Key Laboratory of Nonlinear Mechanics (LNM) and Beijing Key Laboratory of Engineered Construction and Mechanobiology, Institute of Mechanics, Chinese Academy of Sciences, Beijing, China
| | - Xiaohuan Wang
- State Key Laboratory of Nonlinear Mechanics (LNM) and Beijing Key Laboratory of Engineered Construction and Mechanobiology, Institute of Mechanics, Chinese Academy of Sciences, Beijing, China
- School of Engineering Science, University of Chinese Academy of Sciences, Beijing, China
| | - Helong Wu
- College of Mechanical Engineering, Zhejiang University of Technology, Hangzhou, China
| | - Yingfeng Shao
- State Key Laboratory of Nonlinear Mechanics (LNM) and Beijing Key Laboratory of Engineered Construction and Mechanobiology, Institute of Mechanics, Chinese Academy of Sciences, Beijing, China
| | - Huaping Wu
- College of Mechanical Engineering, Zhejiang University of Technology, Hangzhou, China
| | - Fan Song
- State Key Laboratory of Nonlinear Mechanics (LNM) and Beijing Key Laboratory of Engineered Construction and Mechanobiology, Institute of Mechanics, Chinese Academy of Sciences, Beijing, China
- School of Engineering Science, University of Chinese Academy of Sciences, Beijing, China
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34
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Li L, Hu J, Shi X, Różycki B, Song F. Interplay between cooperativity of intercellular receptor-ligand binding and coalescence of nanoscale lipid clusters in adhering membranes. SOFT MATTER 2021; 17:1912-1920. [PMID: 33416062 DOI: 10.1039/d0sm01904f] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Adhesion of biological cells is mediated by the specific binding of receptors and ligands which are typically large proteins spanning through the plasma membranes of the contacting cells. The receptors and ligands can exhibit affinity for nanoscale lipid clusters that form within the plasma membrane. A central question is how these nanoscale lipid clusters physically affect and respond to the receptor-ligand binding during cell adhesion. Within the framework of classical statistical mechanics we find that the receptor-ligand binding reduces the threshold energy for lipid clusters to coalesce into mesoscale domains by up to ∼50%, and that the formation of these domains induces significant cooperativity of the receptor-ligand binding. The interplay between the receptor-ligand binding cooperativity and the lipid domain formation manifests acute sensitivity of the membrane system to changes in control parameters. This sensitivity can be crucial in cell signaling and immune responses.
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Affiliation(s)
- Long Li
- State Key Laboratory of Nonlinear Mechanics and Beijing Key Laboratory of Engineered Construction and Mechanobiology, Institute of Mechanics, Chinese Academy of Sciences, Beijing, China.
| | - Jinglei Hu
- Kuang Yaming Honors School and Institute for Brain Sciences, Nanjing University, Nanjing, China.
| | - Xinghua Shi
- National Center for Nanoscience and Technology of China, Beijing, China
| | - Bartosz Różycki
- Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, Warsaw, Poland.
| | - Fan Song
- State Key Laboratory of Nonlinear Mechanics and Beijing Key Laboratory of Engineered Construction and Mechanobiology, Institute of Mechanics, Chinese Academy of Sciences, Beijing, China. and School of Engineering Science, University of Chinese Academy of Sciences, Beijing, China
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35
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Dam T, Junghans V, Humphrey J, Chouliara M, Jönsson P. Calcium Signaling in T Cells Is Induced by Binding to Nickel-Chelating Lipids in Supported Lipid Bilayers. Front Physiol 2021; 11:613367. [PMID: 33551841 PMCID: PMC7859345 DOI: 10.3389/fphys.2020.613367] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Accepted: 12/30/2020] [Indexed: 12/26/2022] Open
Abstract
Supported lipid bilayers (SLBs) are one of the most common cell-membrane model systems to study cell-cell interactions. Nickel-chelating lipids are frequently used to functionalize the SLB with polyhistidine-tagged ligands. We show here that these lipids by themselves can induce calcium signaling in T cells, also when having protein ligands on the SLB. This is important to avoid "false" signaling events in cell studies with SLBs, but also to better understand the molecular mechanisms involved in T-cell signaling. Jurkat T cells transfected with the non-signaling molecule rat CD48 were found to bind to ligand-free SLBs containing ≥2 wt% nickel-chelating lipids upon which calcium signaling was induced. This signaling fraction steadily increased from 24 to 60% when increasing the amount of nickel-chelating lipids from 2 to 10 wt%. Both the signaling fraction and signaling time did not change significantly compared to ligand-free SLBs when adding the CD48-ligand rat CD2 to the SLB. Blocking the SLB with bovine serum albumin reduced the signaling fraction to 11%, while preserving CD2 binding and the exclusion of the phosphatase CD45 from the cell-SLB contacts. Thus, CD45 exclusion alone was not sufficient to result in calcium signaling. In addition, more cells signaled on ligand-free SLBs with copper-chelating lipids instead of nickel-chelating lipids and the signaling was found to be predominantly via T-cell receptor (TCR) triggering. Hence, it is possible that the nickel-chelating lipids act as ligands to the cell's TCRs, an interaction that needs to be blocked to avoid unwanted cell activation.
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Affiliation(s)
- Tommy Dam
- Department of Chemistry, Lund University, Lund, Sweden
| | | | - Jane Humphrey
- Department of Chemistry, University of Cambridge, Cambridge, United Kingdom
| | | | - Peter Jönsson
- Department of Chemistry, Lund University, Lund, Sweden
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36
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Clemens L, Dushek O, Allard J. Intrinsic Disorder in the T Cell Receptor Creates Cooperativity and Controls ZAP70 Binding. Biophys J 2020; 120:379-392. [PMID: 33285117 PMCID: PMC7840419 DOI: 10.1016/j.bpj.2020.11.2266] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 10/24/2020] [Accepted: 11/19/2020] [Indexed: 12/31/2022] Open
Abstract
Many immunoreceptors have cytoplasmic domains that are intrinsically disordered (i.e., have high configurational entropy), have multiple sites of posttranslational modification (e.g., tyrosine phosphorylation), and participate in nonlinear signaling pathways (e.g., exhibiting switch-like behavior). Several hypotheses to explain the origin of these nonlinearities fall under the broad hypothesis that modification at one site changes the immunoreceptor’s entropy, which in turn changes further modification dynamics. Here, we use coarse-grain simulation to study three scenarios, all related to the chains that constitute the T cell receptor (TCR). We find that first, if phosphorylation induces local changes in the flexibility of the TCR ζ-chain, this naturally leads to rate enhancements and cooperativity. Second, we find that TCR CD3ɛ can provide a switch by modulating its residence in the plasma membrane. By constraining our model to be consistent with the previous observation that both basic residues and phosphorylation control membrane residence, we find that there is only a moderate rate enhancement of 10% between first and subsequent phosphorylation events. Third, we find that volume constraints do not limit the number of ZAP70s that can bind the TCR but that entropic penalties lead to a 200-fold decrease in binding rate by the seventh ZAP70, potentially explaining the observation that each TCR has around six ZAP70 molecules bound after receptor triggering. In all three scenarios, our results demonstrate that phenomena that change an immunoreceptor chain’s entropy (stiffening, confinement to a membrane, and multiple simultaneous binding) can lead to nonlinearities (rate enhancement, switching, and negative cooperativity) in how the receptor participates in signaling. These polymer-entropy-driven nonlinearities may augment the nonlinearities that arise from, e.g., kinetic proofreading and cluster formation. They also suggest different design strategies for engineered receptors, e.g., whether or not to put signaling modules on one chain or multiple clustered chains.
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Affiliation(s)
- Lara Clemens
- Center for Complex Biological Systems, University of California Irvine, Irvine, California
| | - Omer Dushek
- Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
| | - Jun Allard
- Center for Complex Biological Systems, University of California Irvine, Irvine, California; Department of Mathematics and Department of Physics and Astronomy, University of California Irvine, Irvine, California.
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37
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How the T cell signaling network processes information to discriminate between self and agonist ligands. Proc Natl Acad Sci U S A 2020; 117:26020-26030. [PMID: 33020303 DOI: 10.1073/pnas.2008303117] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
T cells exhibit remarkable sensitivity and selectivity in detecting and responding to agonist peptides (p) bound to MHC molecules in a sea of self pMHC molecules. Despite much work, understanding of the underlying mechanisms of distinguishing such ligands remains incomplete. Here, we quantify T cell discriminatory capacity using channel capacity, a direct measure of the signaling network's ability to discriminate between antigen-presenting cells (APCs) displaying either self ligands or a mixture of self and agonist ligands. This metric shows how differences in information content between these two types of peptidomes are decoded by the topology and rates of kinetic proofreading signaling steps inside T cells. Using channel capacity, we constructed numerically substantiated hypotheses to explain the discriminatory role of a recently identified slow LAT Y132 phosphorylation step. Our results revealed that in addition to the number and kinetics of sequential signaling steps, a key determinant of discriminatory capability is spatial localization of a minimum number of these steps to the engaged TCR. Biochemical and imaging experiments support these findings. Our results also reveal the discriminatory role of early negative feedback and necessary amplification conferred by late positive feedback.
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38
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Chung JK, Huang WYC, Carbone CB, Nocka LM, Parikh AN, Vale RD, Groves JT. Coupled membrane lipid miscibility and phosphotyrosine-driven protein condensation phase transitions. Biophys J 2020; 120:1257-1265. [PMID: 33080222 DOI: 10.1016/j.bpj.2020.09.017] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 09/15/2020] [Accepted: 09/17/2020] [Indexed: 12/18/2022] Open
Abstract
Lipid miscibility phase separation has long been considered to be a central element of cell membrane organization. More recently, protein condensation phase transitions, into three-dimensional droplets or in two-dimensional lattices on membrane surfaces, have emerged as another important organizational principle within cells. Here, we reconstitute the linker for activation of T cells (LAT):growth-factor-receptor-bound protein 2 (Grb2):son of sevenless (SOS) protein condensation on the surface of giant unilamellar vesicles capable of undergoing lipid phase separations. Our results indicate that the assembly of the protein condensate on the membrane surface can drive lipid phase separation. This phase transition occurs isothermally and is governed by tyrosine phosphorylation on LAT. Furthermore, we observe that the induced lipid phase separation drives localization of the SOS substrate, K-Ras, into the LAT:Grb2:SOS protein condensate.
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Affiliation(s)
- Jean K Chung
- Department of Chemistry, University of California, Berkeley, Berkeley, California; The Howard Hughes Medical Institute Summer Institute, Marine Biological Laboratory, Woods Hole, Massachusetts
| | - William Y C Huang
- Department of Chemistry, University of California, Berkeley, Berkeley, California; The Howard Hughes Medical Institute Summer Institute, Marine Biological Laboratory, Woods Hole, Massachusetts
| | - Catherine B Carbone
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, California; The Howard Hughes Medical Institute Summer Institute, Marine Biological Laboratory, Woods Hole, Massachusetts
| | - Laura M Nocka
- Department of Chemistry, University of California, Berkeley, Berkeley, California
| | - Atul N Parikh
- Department of Biomedical Engineering, University of California, Davis, Davis, California
| | - Ronald D Vale
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, California; The Howard Hughes Medical Institute Summer Institute, Marine Biological Laboratory, Woods Hole, Massachusetts
| | - Jay T Groves
- Department of Chemistry, University of California, Berkeley, Berkeley, California; The Howard Hughes Medical Institute Summer Institute, Marine Biological Laboratory, Woods Hole, Massachusetts.
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39
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Morrissey MA, Kern N, Vale RD. CD47 Ligation Repositions the Inhibitory Receptor SIRPA to Suppress Integrin Activation and Phagocytosis. Immunity 2020; 53:290-302.e6. [PMID: 32768386 PMCID: PMC7453839 DOI: 10.1016/j.immuni.2020.07.008] [Citation(s) in RCA: 113] [Impact Index Per Article: 28.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2019] [Revised: 05/19/2020] [Accepted: 07/10/2020] [Indexed: 01/29/2023]
Abstract
CD47 acts as a "don't eat me" signal that protects cells from phagocytosis by binding and activating its receptor SIPRA on macrophages. CD47 suppresses multiple different pro-engulfment "eat me" signals, including immunoglobulin G (IgG), complement, and calreticulin, on distinct target cells. This complexity has limited understanding of how the "don't eat me" signal is transduced biochemically. Here, we utilized a reconstituted system with a defined set of signals to interrogate the mechanism of SIRPA activation and its downstream targets. CD47 ligation altered SIRPA localization, positioning SIRPA for activation at the phagocytic synapse. At the phagocytic synapse, SIRPA inhibited integrin activation to limit macrophage spreading across the surface of the engulfment target. Chemical reactivation of integrin bypassed CD47-mediated inhibition and rescued engulfment, similar to the effect of a CD47 function-blocking antibody. Thus, the CD47-SIRPA axis suppresses phagocytosis by inhibiting inside-out activation of integrin signaling in the macrophage, with implications to cancer immunotherapy applications.
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Affiliation(s)
- Meghan A Morrissey
- Department of Cellular and Molecular Pharmacology, University of California San Francisco, San Francisco, CA 94158, USA; Howard Hughes Medical Institute, University of California San Francisco, San Francisco, CA 94158, USA
| | - Nadja Kern
- Department of Cellular and Molecular Pharmacology, University of California San Francisco, San Francisco, CA 94158, USA; Howard Hughes Medical Institute, University of California San Francisco, San Francisco, CA 94158, USA
| | - Ronald D Vale
- Department of Cellular and Molecular Pharmacology, University of California San Francisco, San Francisco, CA 94158, USA; Howard Hughes Medical Institute, University of California San Francisco, San Francisco, CA 94158, USA.
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40
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Junghans V, Chouliara M, Santos AM, Hatherley D, Petersen J, Dam T, Svensson LM, Rossjohn J, Davis SJ, Jönsson P. Effects of a local auxiliary protein on the two-dimensional affinity of a TCR-peptide MHC interaction. J Cell Sci 2020; 133:jcs245985. [PMID: 32591485 DOI: 10.1242/jcs.245985] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Accepted: 06/11/2020] [Indexed: 12/20/2022] Open
Abstract
The affinity of T-cell receptors (TCRs) for major histocompatibility complex molecules (MHCs) presenting cognate antigens likely determines whether T cells initiate immune responses, or not. There exist few measurements of two-dimensional (2D) TCR-MHC interactions, and the effect of auxiliary proteins on binding is unexplored. Here, Jurkat T-cells expressing the MHC molecule HLA-DQ8-glia-α1 and the ligand of an adhesion protein (rat CD2) were allowed to bind supported lipid bilayers (SLBs) presenting fluorescently labelled L3-12 TCR and rat CD2, allowing measurements of binding unconfounded by cell signaling effects or co-receptor binding. The 2D Kd for L3-12 TCR binding to HLA-DQ8-glia-α1, of 14±5 molecules/μm2 (mean±s.d.), was only marginally influenced by including CD2 up to ∼200 bound molecules/μm2 but higher CD2 densities reduced the affinity up to 1.9-fold. Cell-SLB contact size increased steadily with ligand density without affecting binding for contacts at up to ∼20% of total cell area, but beyond this lamellipodia appeared, giving an apparent increase in bound receptors of up to 50%. Our findings show how parameters other than the specific protein-protein interaction can influence binding behavior at cell-cell contacts.
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Affiliation(s)
| | - Manto Chouliara
- Department of Chemistry, Lund University, 221 00 Lund, Sweden
| | - Ana Mafalda Santos
- Radcliffe Department of Medicine, John Radcliffe Hospital, University of Oxford; and Medical Research Council Human Immunology Unit, John Radcliffe Hospital, University of Oxford, OX3 9DS Oxford, UK
| | - Deborah Hatherley
- Radcliffe Department of Medicine, John Radcliffe Hospital, University of Oxford; and Medical Research Council Human Immunology Unit, John Radcliffe Hospital, University of Oxford, OX3 9DS Oxford, UK
| | - Jan Petersen
- Infection and Immunity Program & Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, Victoria 3800, Australia
- Australian Research Council Centre of Excellence in Advanced Molecular Imaging, Monash University, Clayton, Victoria 3800, Australia
| | - Tommy Dam
- Department of Chemistry, Lund University, 221 00 Lund, Sweden
| | - Lena M Svensson
- Department of Experimental Medical Science, Lund University, 221 00 Lund, Sweden; and School of Medical Sciences, Örebro University, 701 82 Örebro, Sweden
| | - Jamie Rossjohn
- Infection and Immunity Program & Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, Victoria 3800, Australia
- Australian Research Council Centre of Excellence in Advanced Molecular Imaging, Monash University, Clayton, Victoria 3800, Australia
- Institute of Infection and Immunity, Cardiff University School of Medicine, Heath Park, Cardiff CF14 4XN, UK
| | - Simon J Davis
- Radcliffe Department of Medicine, John Radcliffe Hospital, University of Oxford; and Medical Research Council Human Immunology Unit, John Radcliffe Hospital, University of Oxford, OX3 9DS Oxford, UK
| | - Peter Jönsson
- Department of Chemistry, Lund University, 221 00 Lund, Sweden
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41
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Bhattacharyya ND, Feng CG. Regulation of T Helper Cell Fate by TCR Signal Strength. Front Immunol 2020; 11:624. [PMID: 32508803 PMCID: PMC7248325 DOI: 10.3389/fimmu.2020.00624] [Citation(s) in RCA: 60] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Accepted: 03/19/2020] [Indexed: 12/16/2022] Open
Abstract
T cells are critical in orchestrating protective immune responses to cancer and an array of pathogens. The interaction between a peptide MHC (pMHC) complex on antigen presenting cells (APCs) and T cell receptors (TCRs) on T cells initiates T cell activation, division, and clonal expansion in secondary lymphoid organs. T cells must also integrate multiple T cell-intrinsic and extrinsic signals to acquire the effector functions essential for the defense against invading microbes. In the case of T helper cell differentiation, while innate cytokines have been demonstrated to shape effector CD4+ T lymphocyte function, the contribution of TCR signaling strength to T helper cell differentiation is less understood. In this review, we summarize the signaling cascades regulated by the strength of TCR stimulation. Various mechanisms in which TCR signal strength controls T helper cell expansion and differentiation are also discussed.
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Affiliation(s)
- Nayan D Bhattacharyya
- Immunology and Host Defense Group, Discipline of Infectious Diseases and Immunology, School of Medical Sciences, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia.,Tuberculosis Research Program, Centenary Institute, The University of Sydney, Sydney, NSW, Australia
| | - Carl G Feng
- Immunology and Host Defense Group, Discipline of Infectious Diseases and Immunology, School of Medical Sciences, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia.,Tuberculosis Research Program, Centenary Institute, The University of Sydney, Sydney, NSW, Australia
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42
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Ma Y, Lim YJ, Benda A, Lou J, Goyette J, Gaus K. Clustering of the ζ-Chain Can Initiate T Cell Receptor Signaling. Int J Mol Sci 2020; 21:ijms21103498. [PMID: 32429097 PMCID: PMC7279048 DOI: 10.3390/ijms21103498] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 05/11/2020] [Accepted: 05/13/2020] [Indexed: 11/16/2022] Open
Abstract
T cell activation is initiated when ligand binding to the T cell receptor (TCR) triggers intracellular phosphorylation of the TCR-CD3 complex. However, it remains unknown how biophysical properties of TCR engagement result in biochemical phosphorylation events. Here, we constructed an optogenetic tool that induces spatial clustering of ζ-chain in a light controlled manner. We showed that spatial clustering of the ζ-chain intracellular tail alone was sufficient to initialize T cell triggering including phosphorylation of ζ-chain, Zap70, PLCγ, ERK and initiated Ca2+ flux. In reconstituted COS-7 cells, only Lck expression was required to initiate ζ-chain phosphorylation upon ζ-chain clustering, which leads to the recruitment of tandem SH2 domain of Zap70 from cell cytosol to the newly formed ζ-chain clusters at the plasma membrane. Taken together, our data demonstrated the biophysical relevance of receptor clustering in TCR signaling.
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Affiliation(s)
- Yuanqing Ma
- EMBL Australia Node in Single Molecule Science, School of Medical Sciences, The University of New South Wales, 2052 Sydney, Australia; (J.L.); (J.G.)
- ARC Centre of Excellence in Advanced Molecular Imaging, The University of New South Wales, 2052 Sydney, Australia
- Correspondence: (Y.M.); (K.G.)
| | - Yean J. Lim
- ACRF Department of Cancer Biology and Therapeutics, The John Curtin School of Medical Research, The Australian National University, 131 Garran Road, 2601 Canberra, Australia;
- Research School of Electrical, Energy and Materials Engineering, College of Engineering and Computer Science, The Australian National University, 31 North Road, 2601 Canberra, Australia
| | - Aleš Benda
- IMCF at BIOCEV, Faculty of Science, Charles University, Průmyslová 595, 25250 Vestec, Czech Republic;
| | - Jieqiong Lou
- EMBL Australia Node in Single Molecule Science, School of Medical Sciences, The University of New South Wales, 2052 Sydney, Australia; (J.L.); (J.G.)
- ARC Centre of Excellence in Advanced Molecular Imaging, The University of New South Wales, 2052 Sydney, Australia
- School of Physics, University of Melbourne, Melbourne, VIC 3010, Australia
- Department of Biochemistry and Molecular Biology, Bio21 Institute, University of Melbourne, Melbourne, VIC 3010, Australia
| | - Jesse Goyette
- EMBL Australia Node in Single Molecule Science, School of Medical Sciences, The University of New South Wales, 2052 Sydney, Australia; (J.L.); (J.G.)
- ARC Centre of Excellence in Advanced Molecular Imaging, The University of New South Wales, 2052 Sydney, Australia
| | - Katharina Gaus
- EMBL Australia Node in Single Molecule Science, School of Medical Sciences, The University of New South Wales, 2052 Sydney, Australia; (J.L.); (J.G.)
- ARC Centre of Excellence in Advanced Molecular Imaging, The University of New South Wales, 2052 Sydney, Australia
- Correspondence: (Y.M.); (K.G.)
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43
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Garcia E, Ismail S. Spatiotemporal Regulation of Signaling: Focus on T Cell Activation and the Immunological Synapse. Int J Mol Sci 2020; 21:E3283. [PMID: 32384769 PMCID: PMC7247333 DOI: 10.3390/ijms21093283] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 05/01/2020] [Accepted: 05/03/2020] [Indexed: 01/22/2023] Open
Abstract
In a signaling network, not only the functions of molecules are important but when (temporal) and where (spatial) those functions are exerted and orchestrated is what defines the signaling output. To temporally and spatially modulate signaling events, cells generate specialized functional domains with variable lifetime and size that concentrate signaling molecules, enhancing their transduction potential. The plasma membrane is a key in this regulation, as it constitutes a primary signaling hub that integrates signals within and across the membrane. Here, we examine some of the mechanisms that cells exhibit to spatiotemporally regulate signal transduction, focusing on the early events of T cell activation from triggering of T cell receptor to formation and maturation of the immunological synapse.
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Affiliation(s)
- Esther Garcia
- CR-UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow G61 1BD, UK
| | - Shehab Ismail
- CR-UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow G61 1BD, UK
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44
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Lin JJ, O'Donoghue GP, Wilhelm KB, Coyle MP, Low-Nam ST, Fay NC, Alfieri KN, Groves JT. Membrane Association Transforms an Inert Anti-TCRβ Fab' Ligand into a Potent T Cell Receptor Agonist. Biophys J 2020; 118:2879-2893. [PMID: 32407684 DOI: 10.1016/j.bpj.2020.04.018] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Revised: 03/09/2020] [Accepted: 04/13/2020] [Indexed: 12/27/2022] Open
Abstract
The natural peptide-major histocompatibility complex (pMHC) ligand for T cell receptors (TCRs) is inactive from solution yet capable of activating T cells at single-molecule levels when membrane-associated. This distinctive feature stems from the mechanism of TCR activation, which is thought to involve steric phosphatase exclusion as well as direct mechanical forces. It is possible to defeat this mechanism and activate T cells with solution ligands by cross-linking pMHC or using multivalent antibodies to TCR. However, these widely used strategies activate TCRs through a nonphysiological mechanism and can produce different activation profiles than natural, monovalent, membrane-associated pMHC. Here, we introduce a strictly monovalent anti-TCRβ H57 Fab' ligand that, when coupled to a supported lipid bilayer via DNA complementation, triggers TCRs and activates nuclear translocation of the transcription factor nuclear factor of activated T cells (NFAT) with a similar potency to pMHC in primary murine T cells. Importantly, like monovalent pMHC and unlike bivalent antibodies, monovalent Fab'-DNA triggers TCRs only when physically coupled to the membrane, and only around 100 individual Fab':TCR interactions are necessary to stimulate early T cell activation.
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Affiliation(s)
- Jenny J Lin
- Department of Chemistry, University of California, Berkeley, Berkeley, California
| | - Geoff P O'Donoghue
- Department of Chemistry, University of California, Berkeley, Berkeley, California.
| | - Kiera B Wilhelm
- Department of Chemistry, University of California, Berkeley, Berkeley, California
| | - Michael P Coyle
- Department of Chemistry, University of California, Berkeley, Berkeley, California.
| | - Shalini T Low-Nam
- Department of Chemistry, University of California, Berkeley, Berkeley, California
| | - Nicole C Fay
- Department of Molecular and Cellular Biology, University of California, Berkeley, Berkeley, California
| | - Katherine N Alfieri
- Department of Chemistry, University of California, Berkeley, Berkeley, California
| | - Jay T Groves
- Department of Chemistry, University of California, Berkeley, Berkeley, California.
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45
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Hui E. Understanding T cell signaling using membrane reconstitution. Immunol Rev 2020; 291:44-56. [PMID: 31402497 DOI: 10.1111/imr.12767] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Accepted: 04/02/2019] [Indexed: 12/31/2022]
Abstract
T cells are central players of our immune system, as their functions range from killing tumorous and virus-infected cells to orchestrating the entire immune response. In order for T cells to divide and execute their functions, they must be activated by antigen-presenting cells (APCs) through a cell-cell junction. Extracellular interactions between receptors on T cells and their ligands on APCs trigger signaling cascades comprised of protein-protein interactions, enzymatic reactions, and spatial reorganization events, to either stimulate or repress T cell activation. Plasma membrane is the major platform for T cell signaling. Recruitment of cytosolic proteins to membrane-bound receptors is a common critical step in many signaling pathways. Membranes decrease the dimensionality of protein-protein interactions to enable weak yet biologically important interactions. Membrane resident proteins can phase separate into micro-islands that promote signaling by enriching or excluding signal regulators. Moreover, some membrane lipids can either mediate or regulate cell signaling by interacting with signaling proteins. While it is critical to investigate T cell signaling in a cellular environment, the large number of signaling pathways involved and potential crosstalk have made it difficult to obtain precise, quantitative information on T cell signaling. Reconstitution of purified proteins to model membranes provides a complementary avenue for T cell signaling research. Here, I review recent progress in studying T cell signaling using membrane reconstitution approaches.
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Affiliation(s)
- Enfu Hui
- Section of Cell and Developmental Biology, Division of Biological Sciences, University of California San Diego, La Jolla, California
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46
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Schamel WW, Alarcon B, Minguet S. The TCR is an allosterically regulated macromolecular machinery changing its conformation while working. Immunol Rev 2020; 291:8-25. [PMID: 31402501 DOI: 10.1111/imr.12788] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Accepted: 05/30/2019] [Indexed: 12/13/2022]
Abstract
The αβ T-cell receptor (TCR) is a multiprotein complex controlling the activation of T cells. Although the structure of the complete TCR is not known, cumulative evidence supports that the TCR cycles between different conformational states that are promoted either by thermal motion or by force. These structural transitions determine whether the TCR engages intracellular effectors or not, regulating TCR phosphorylation and signaling. As for other membrane receptors, ligand binding selects and stabilizes the TCR in active conformations, and/or switches the TCR to activating states that were not visited before ligand engagement. Here we review the main models of TCR allostery, that is, ligand binding at TCRαβ changes the structure at CD3 and ζ. (a) The ITAM and proline-rich sequence exposure model, in which the TCR's cytoplasmic tails shield each other and ligand binding exposes them for phosphorylation. (b) The membrane-ITAM model, in which the CD3ε and ζ tails are sequestered inside the membrane and again ligand binding exposes them. (c) The mechanosensor model in which ligand binding exerts force on the TCR, inducing structural changes that allow signaling. Since these models are complementary rather than competing, we propose a unified model that aims to incorporate all existing data.
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Affiliation(s)
- Wolfgang W Schamel
- Department of Immunology, Faculty of Biology, Albert-Ludwigs-University of Freiburg, Freiburg, Germany.,Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Freiburg, Germany.,Center of Chronic Immunodeficiency CCI, University Clinics and Medical Faculty, Freiburg, Germany
| | - Balbino Alarcon
- Centro de Biología Molecular Severo Ochoa, CSIC-UAM, Madrid, Spain
| | - Susana Minguet
- Department of Immunology, Faculty of Biology, Albert-Ludwigs-University of Freiburg, Freiburg, Germany.,Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Freiburg, Germany.,Center of Chronic Immunodeficiency CCI, University Clinics and Medical Faculty, Freiburg, Germany
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47
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Mariuzza RA, Agnihotri P, Orban J. The structural basis of T-cell receptor (TCR) activation: An enduring enigma. J Biol Chem 2020. [DOI: 10.1016/s0021-9258(17)49904-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
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48
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Mariuzza RA, Agnihotri P, Orban J. The structural basis of T-cell receptor (TCR) activation: An enduring enigma. J Biol Chem 2019; 295:914-925. [PMID: 31848223 DOI: 10.1074/jbc.rev119.009411] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
T cells are critical for protective immune responses to pathogens and tumors. The T-cell receptor (TCR)-CD3 complex is composed of a diverse αβ TCR heterodimer noncovalently associated with the invariant CD3 dimers CD3ϵγ, CD3ϵδ, and CD3ζζ. The TCR mediates recognition of antigenic peptides bound to MHC molecules (pMHC), whereas the CD3 molecules transduce activation signals to the T cell. Whereas much is known about downstream T-cell signaling pathways, the mechanism whereby TCR engagement by pMHC is first communicated to the CD3 signaling apparatus, a process termed early T-cell activation, remains largely a mystery. In this review, we examine the molecular basis for TCR activation in light of the recently determined cryoEM structure of a complete TCR-CD3 complex. This structure provides an unprecedented opportunity to assess various signaling models that have been proposed for the TCR. We review evidence from single-molecule and structural studies for force-induced conformational changes in the TCR-CD3 complex, for dynamically-driven TCR allostery, and for pMHC-induced structural changes in the transmembrane and cytoplasmic regions of CD3 subunits. We identify major knowledge gaps that must be filled in order to arrive at a comprehensive model of TCR activation that explains, at the molecular level, how pMHC-specific information is transmitted across the T-cell membrane to initiate intracellular signaling. An in-depth understanding of this process will accelerate the rational design of immunotherapeutic agents targeting the TCR-CD3 complex.
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Affiliation(s)
- Roy A Mariuzza
- W. M. Keck Laboratory for Structural Biology, University of Maryland Institute for Bioscience and Biotechnology Research, Rockville, Maryland 20850 .,Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, Maryland 20742
| | - Pragati Agnihotri
- W. M. Keck Laboratory for Structural Biology, University of Maryland Institute for Bioscience and Biotechnology Research, Rockville, Maryland 20850.,Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, Maryland 20742
| | - John Orban
- W. M. Keck Laboratory for Structural Biology, University of Maryland Institute for Bioscience and Biotechnology Research, Rockville, Maryland 20850 .,Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742
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49
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Kaitao L, William R, Zhou Y, Cheng Z. Single-molecule investigations of T-cell activation. CURRENT OPINION IN BIOMEDICAL ENGINEERING 2019; 12:102-110. [PMID: 32296738 PMCID: PMC7158867 DOI: 10.1016/j.cobme.2019.10.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
T-cell activation is the central event governing its development, differentiation, and effector functions. T-cell activation is initiated by the direct physical interaction of the T cell antigen receptor (TCR) with cognate peptide presented by the major histocompatibility complex (pMHC) molecule expressed on the antigen presenting cell (APC) surface. Since the identification of TCR as the only receptor for antigen on T cells three decades ago, studies have elucidated the major molecular players and signaling events responding to TCR stimulation. However, the question of how the physical event of pMHC binding is converted across the membrane into chemical events to initiate signal transduction remains elusive. Here we review recent investigations of T-cell activation using single-molecule force and fluorescence techniques that shed new light on this key question.
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Affiliation(s)
- Li Kaitao
- Wallace H. Coulter Department of Biomedical Engineering
- Institute for Bioengineering and Biosciences, Georgia Institute of Technology, Atlanta, GA 30332
| | - Rittase William
- Wallace H. Coulter Department of Biomedical Engineering
- Institute for Bioengineering and Biosciences, Georgia Institute of Technology, Atlanta, GA 30332
| | - Yuan Zhou
- George W. Woodruff School of Mechanical Engineering
- Institute for Bioengineering and Biosciences, Georgia Institute of Technology, Atlanta, GA 30332
| | - Zhu Cheng
- Wallace H. Coulter Department of Biomedical Engineering
- George W. Woodruff School of Mechanical Engineering
- Institute for Bioengineering and Biosciences, Georgia Institute of Technology, Atlanta, GA 30332
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50
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Zhang Y, Clemens L, Goyette J, Allard J, Dushek O, Isaacson SA. The Influence of Molecular Reach and Diffusivity on the Efficacy of Membrane-Confined Reactions. Biophys J 2019; 117:1189-1201. [PMID: 31543263 PMCID: PMC6818170 DOI: 10.1016/j.bpj.2019.08.023] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Revised: 07/30/2019] [Accepted: 08/22/2019] [Indexed: 11/15/2022] Open
Abstract
Signaling by surface receptors often relies on tethered reactions whereby an enzyme bound to the cytoplasmic tail of a receptor catalyzes reactions on substrates within reach. The overall length and stiffness of the receptor tail, the enzyme, and the substrate determine a biophysical parameter termed the molecular reach of the reaction. This parameter determines the probability that the receptor-tethered enzyme will contact the substrate in the volume proximal to the membrane when separated by different distances within the membrane plane. In this work, we develop particle-based stochastic reaction-diffusion models to study the interplay between molecular reach and diffusion. We find that increasing the molecular reach can increase reaction efficacy for slowly diffusing receptors, whereas for rapidly diffusing receptors, increasing molecular reach reduces reaction efficacy. In contrast, if reactions are forced to take place within the two-dimensional plasma membrane instead of the three-dimensional volume proximal to it or if molecules diffuse in three dimensions, increasing molecular reach increases reaction efficacy for all diffusivities. We show results in the context of immune checkpoint receptors (PD-1 dephosphorylating CD28), a standard opposing kinase-phosphatase reaction, and a minimal two-particle model. The work highlights the importance of the three-dimensional nature of many two-dimensional membrane-confined interactions, illustrating a role for molecular reach in controlling biochemical reactions.
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Affiliation(s)
- Ying Zhang
- Department of Mathematics and Statistics, Boston University, Boston, Massachusetts
| | - Lara Clemens
- Center for Complex Biological Systems, University of California-Irvine, Irvine, California
| | - Jesse Goyette
- School of Medical Sciences, University of New South Wales, Sydney, Australia
| | - Jun Allard
- Center for Complex Biological Systems, University of California-Irvine, Irvine, California
| | - Omer Dushek
- Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom.
| | - Samuel A Isaacson
- Department of Mathematics and Statistics, Boston University, Boston, Massachusetts.
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